324 324-Piece Set

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-2226
Advertised Part Count(s): 324 pieces
First Year Confirmed Available: 1966 (USA)
Sears exclusive, USA only.
Most Likely Retirement Date: 1966
The set does not return in the 1967 Sears Wishbook, replaced by the 335-piece set (later known as the 835 Advanced Builders Set).
Last Year Seen Available: 1966
Aliases: 324-Piece Set, 49-4742, 463241
Retail Price(s): $6.22 (USA)
Rarity Score (Index): 6/7
Known Box/Packing Variants
As the 324 was only produced for one season, it likely has no variants.
Box/Overview
The 324-Piece Set, while being rather elusive, has an interesting association and solves a mystery. For context, the 324 set only appears in the Sears catalog in 1966 and was replaced by a set with a similar piece count in 1967: 835 Advanced Builders Set (known only as the 335-Piece Set at the time).
Curiously, the form number on the 835's instructions date them to 1966, even though the 335-piece set did not appear until 1967. Thus, the 324 set must have been the source for the 835's instructions.

The distinct house model was only ever used in marketing in association with the 324/335/835, appearing in the 1966 Sears Wishbook as well as subsequent wishbooks.
So while the 324 is essentially the same set as the 835 just with a different piece count, I've created two separate catalog entries onsite to make the distinction between the versions clearer (as well as make quick reference easier). In the future I may merge the two articles.
The 324-piece set should also not be confused with the 326-piece set/326 Suburban Set. While very close in piece count, their assortments and distribution were different. The easiest way to tell is the catalog number on the box, as Sears sets will have Sears catalog numbers.
Contents
Similar to early copies of the 835, loose copies of the 324 seem to be missing trees:

Though note that this may be because they're lost overtime and assumed to not be LEGO.