Yeah....you're right. My terminology could have been better in describing that.
The output support is damaged. It's not dug in considerably, but it is not smooth. It also doesn't look the same as the 904.
It is the low reverse drum that has the play. I should have assessed it better before posting.
When I have some time I'll take a close look at it. I'm pretty sure with both transmissions here and apart I should be able to correct any problems I find.
I still haven't gone into or studied the valve body entirely yet so I'll look at that as well.
The problem could be there. I'll post more when I find something