You just change the appropriate type pallets/and keytops not the entire wheel
Here is a photo of the Finance pallets and tops for my 26.
Its a pretty easy conversion. Mine came already set up for comm and the finance set was
tucked under the motor in that oily brown envelope in the second photo. It was a pleasant surprise
you normally never find the other set of pallets and tops.
Talk to Paul (Mr.RTTY) mr_rtty@pacbell.net he might have some 26 bits and odds and ends.