MTB frame set, 142x12mm, 650b to find cheap

[Herman Toothrot]

I've quite a lot of bits in the garage and want to build up a cheap pub bike, central to it are a set of 650b wheels I have spare, rear 142x12mm - trying to work out what manufacturer frames I should be searching for, I know it's the new standard but it's surprising that the cheaper end of most seem to still be 135mm, I want something that won't draw attention and who the have cost me much if it does get nicked.