Is this transaxle swap possible?

I have 2 Yard-Machines (MTD) mowers that I'd like to swap the transaxle on. I want to use the Hydrostatic transaxle from a 1997 Series 695 and put it into an earlier similar model that has a 7 speed transaxle and is 4-wheel steer. I just bought that one and haven't found the model info yet. I know I would have to use the pedal assemblies and fenders, running boards etc. from the donor. On the surface it looks to me like it might be doable. I can get more info on the receiver machine but I thought I'd start by asking if it is even plausible.