I found some old 'boards on ebay that had doubleshot keycaps, made a list of all the ones that had "make offer". Then, I made low offers, and two accepted.
Of the two, one sent the whole board, and the other just the keycaps. A good deal either way.
Both were yellow, but should take about 3 weeks to retrobrite in my weak solution.
I plan to resell one set after they're all done retrobriting.