I opened a PhotoFast CR-5400 to see how it was made. Unfortunately, if you had dreams of some sort of simple pin-to-pin adapter, you're going to be disapointed. The adapter has a 64-pin surface-mount IC (labled "PhotoFast 54v1"). Since the chip is obviously properiatary, you're not going to find specs on it anywhere.
Out of the 64 pins on the 54v1 chip you can automatically account for 26 of them (8 pins per microSD card (x2 cards) plus the 10 pins for the MS Pro Duo connection). That leaves a lot of pins on the 54v1 unaccounted for. The entire device is painted with a flat black coating that seems to be baked on (paint remover couldn't dissolve it) that makes it nearly impossible to trace the circuits, but I'm working it.