While I have found some diecast vehicles in 1/22 scale, they're too "new" for my layout. There are a few on Ebay right now( mostly 1930's Packards) ,and they are in kit form made by Hubley/Gabriel.
I have found period correct vehicles (1910 to 1920) in 1/20 scale,and while there is a broader array of vehicles available in 1/24 scale, I'm going ahead and purchasing a couple of more 1/20 scale diecast vehicles .
In fact, I still plan on using the 1/24th vehicles that I already bought , but with my smaller Kalamazoo, Lionel, and HLW trains ,as those 3 manufacturers trains are on a smaller scale than Bachmann,LGB, or Aristocraft's trains are in.
I just bought a 1/20 Hubley 1909 Model T Touring car, and am also considering a 1/20 1909 Model T Sport Runabout.
I really like those 1/22 scale Packards, but ,as I stated, they're all too "new" for what I'm trying to get done.
Nice layout, Zerogee. Some of those buildings ( real life versions of them ) look like they'd be right at home on the shores of Lake Tahoe!