Ford Mile-o-matic question

Friend's Edsel has one of these Mile-o-matic jobbers. Seems that now reverse has gone out more or less, kinda grinds but doesnt engage. The rest of the gears still work.
From my experience when reverse goes so does first. Is there something different about this or maybe something to be looking at?
It has/had a small leak that doesnt want to be located, things under the car stay very dry. It's sitting in my driveway now and now that it hasnt moved for a few days there is some wet on the trans pan and a puddle underneath it.

Suggestions? or is it just time for a full rebuild... or maybe a swap?

 

wow, nobody?

 

I think it is time for a rebuild. All rubber seals inside and out are probably hard.