I've got 4 of them along with 3 blow ups. Shipping would kill you. I'm sure you could find one cheaper at one of the local junk yards. Just ask them if you could try a few and see if they would fit.
I've got a 72, 74, 76, and 77. I'll check tomorrow to make sure, but I think they changed in 76 or 77. Not sure. I stripped out a 75 for my 72. I was surprised as to what interchanged.