"Scale" cars and vehicles?

Diecast Direct has some inexpensive 30's vehicles in 1/43. You can also watch eBay. There are a lot of 1/43 die-cast cars and trucks that are now out of production but still readily available on the secondary market. Manufacturers include Ertl, Solido, Eligor, Corgi, Yat Ming, Road Champions, Matchbox, and others. '32 Ford roadsters are quite common. Ertl makes a really nice one that you can pick up for ten bucks or so. There are also lots of Ford pickups out there. Sedans are harder to find; delivery trucks are easy. As is the case with more modern cars, luxury brands and convertibles are more available than plain old sedans. Cords and Duesenbergs are pretty common; Chevys much less so. 

1/43 cars are kind of big for 027, but most people use them anyway. Since 027 isn't really scale, you just accept that they are out of proportion. If you prefer undersize to oversize, Hot Wheels and Johnny Lightning are 1/64 scale and they make a lot of older models. 

One other thing I forgot - check out the OGR Buy/Sell board. Die-cast cars and trucks show up there fairly often. There's a guy who who goes by the screen name of BK. He posts every couple of weeks and sometimes has interesting items at good prices. I've bought a Plymouth pickup, a Ford convertible, a Studebaker hearse and probably some other stuff from him. 

One now defunct mfr. who made a variety of sedans, 1935 Fords, 1940 Packards,

was Rextoy...originally about $30 new.  Brooklins, NOT cheap, but found for less used,

are on the bay in 1930 Ford coupes and victorias now, they only made one 1937

Chevy coupe, and have a spectrum of Buicks, but these are recent and can exceed

$100 each.

Thanks, gents!  I will follow up on your suggestions.