Clutch failures do not selectively pick on any one gear. No, you've
got a new problem now. Check interlink in shift linkage as that was
disturbed by removing the transmission unless the guy doing the
clutch pulled the engine instead of the transaxle (like I usually do ....
it's a lot easier). If the linkage is OK then you're looking to take the
unit out and repair/rebuild the unit to fix reverse. WHO or WHOM told
you reverse gear was "gone" as it makes at least a small difference. I
trust no-one. Transmissions are voodoo to most people and some
shops take advantage of that fear.