610 & 1610 Super Wheel Toy
General Information
The following information has been collected from original newspapers, catalogs, and magazines, some of which are freely available for reference below. The rest can be found in the site’s gallery. No aggregate catalogs (BrickLink, Brickset, etc.) were used.
Instructions: H-2083
Note that the Canadian version had a completely different instruction sheet. It can be found in high quality on Daan's flikr.
Advertised Part Count(s): 296 pieces, 297 pieces, 363 pieces (Canadian 1965), 285 pieces (Canadian 1967)
1964 FAO Schwarz Christmas Catalog
1965 Eaton's Christmas Catalog
1967 Eaton's Christmas Catalog
First Year Confirmed Available: 1964 (USA & Canada)
1964 Jordan Marsh Christmas Catalog
The Ottawa Citizen, December 5th, 1964
1610 (canister) exclusive to:
While Spiegel carried the other two canister sets (1605 & 1905), there is no evidence that Spiegel sold the 1610. It is missing entirely from the 1965 Spiegel Christmas Catalog. It's possible Spiegel sold it, but we're currently missing the 1964 catalog. Also note that the Sears catalog doesn't picture the 1610 canister.
610 (tall box) & 1610 were both USA only.
610 (flat box) was Canadian only.
Most Likely Retirement Date:
USA: 1965
The 610 is uniquely the only set from 1961-65 to appear alongside the new 1965 line in promotional images for the prototype 1965 line. As the 610 did not appear for order in the 1966 Dealer Catalog nor the pack in brochure from 1965, as well as considering the set did not return to catalogs in 1966, the set retired in 1965. It uniquely had a later retirement compared to other 1961-1964 sets.
Canada: 1969
It consistently appears in Canadian catalogs/newspapers after 1965 and makes its final appearance in 1969.
Last Year Seen Available: 1969 (Canadian)
The Kingston Whig Standard, October 14th, 1969
Aliases: Super Wheel Toy
Retail Price(s): $9.95 (USA) / $10.95 (Canada)
It should be noted that the Canadian RRP fluctuates over its long production (same with its piece count), the lowest I've found being $8.95 in a 1967 Eaton's catalog.
Discounted Example(s): $4.95 (1965 USA), $6.99 (1969, Canadian)
Rarity Score (Rarity Index):
USA 610: 4/7
USA 1610: 5/7
Canadian 610: 6/7
Known Box/Packing Variants
Similar to the 605 Wheel Toy and 905 Doll Set, the 610 also had a canister variant. It sold at Sears (and likely Spiegel) starting in 1964 and retired after the 1965 Christmas season. It was exclusive to the US.

Infamously, the Canadian version of the 610 is entirely different in both packaging and assortment. It is the first use of the tray format in North America, which we will discuss later. This one shown below is from thebrickshackgrimsby on Instagram, showing an incredibly rare view of the inside:

The Canadian 610 also had instructions different than the USA version. Better instructions, in that they actually showed the assembly of the model. They're linked at the top of this article.
Box/Overview
The 610 Super Wheel Toy released in 1964 as a companion/successor to the 605 Wheel Toy. The set was sort of a deluxe two-in-one, including both the smaller wheels the 605 used and the new larger style, marking their debut in North America. Hence the "super" wheel name.
The US 610 is also the only tall box set to not use a baseplate to cap the top. As the 10x20 baseplates have supports underneath(that the 10x10 baseplates didn't have at the time), it wouldn't have worked. They instead printed the baseplate on the top of the box.
Like most tall box sets, they are notoriously found beat up, like mine:

Contents
The US 610 and 1610 contained roughly the same assortment (though as usual, there's bound to be differences between most copies):
The 1610 likely carried a similar assortment, just repackaged into a canister:

The Canadian version of the set appeared to have a different assortment available to build the locomotive. For example, it included numbered bricks which as far as I'm aware, the US versions never included.
Historical Examples
One must wonder why exactly the Canadian 610 box was such a deep departure from the US version. After all, the 1961-63 Canadian sets only added a price—why was 1964 different?

I see a few options, though these are not exclusive nor exhaustive.
The first is that the tube design was generally not desirable for this set. I don't know that aesthetics are enough to prompt an entire change of box, but the Canadian version has a much better presentation and previous history with the 605/905 sets would have informed the 610's box. Sure, Canada kept the tube format until at least 1969 with smaller mainline sets they produced, but perhaps this set was considered over the threshold.
The second has to do with development/longevity with a little uncertainty. The Canadian version persisted until 1969, long after the US retired the tube format (and the US 610). It's possible the Canadian subsidiary of Samsonite wanted the set to last much longer than the US did and that somehow informed their decision.
The third, and most likely option for me, is that the tall box requires dumping out all the pieces. Hence why tall box sets (especially the 610) are typically destroyed. As the Canadian version places more emphasis on the locomotive model (and the piece count is ~300), it'd be easier to have the pieces organized and accessible in general "bins" rather than strewn all about.
Should I collect this set?
The tall box version? If you see a good one, sure. Not really my cup of tea, but I wouldn't go so far as to steer someone away from it. I'm a little more partial to the canister, but the one that intrigues me the most (and I imagine most other Samsonite collectors) is the Canadian version.
It's such a good example why I'm not too keen on the tube sets. They use vertical space well and all, but the limited ability to present themselves from any one angle starts to make me weary. The box format is so much more interesting, but I also have to remind myself the air of mystery surrounding it is also part of the appeal and is doing a lot of heavy lifting.
I might have a better answer if I thought about it hard enough, but if I had to choose any item as my "white whale", the Canadian 610 would probably be it. I'd love to own one someday and scan the instructions proper.