Well, if you just print to order, you could do any scale someone wanted.
I know of several 3D printers who print to order, payment in advance.
I'd think the problem would be getting your frame price down enough to be really competitive with buying '32 kits that have a lot of other parts, and still make some profit yourself.
There's something of a market for '32 ford frames in 1/12 and 1/16 as well. I'd certainly buy at least one of each, more if they were GOOD.
1/8 is covered with the Revellogram Big Deuce kit parts, but they're kinda spendy, so there's that too.
I have bought 3D parts that are gooey messes prone to warpage, or are brittle, and other 3D parts that seem to be very stable, so apparently no-warp quality CAN be done if you know what you're doing.