Having not used a 82851 myself I can’t say for sure one way or the other.

As long as all the transfer and idle feed holes in the baseplate line up with the ones in Proform body, I don’t see any reason why it wouldn’t work.

Of course there’s no guarantee the Proform body will work any better than the 82851 body.
It might not even work as well on your combo.
But ........ you’ll have both to try.