Yep, my threads were OK as well, just some kind of heavy surface rust.
They must just spin off
I think you'll be OK with the nylock on there.
I went as far as renting the tool to pull clutch but I found the aluminum "snout" was all galled up and the bearing was loose on it
Mine was cooling pretty well with 134a before the compressor went out.
Kudos to doing this on the car! I'll bet you could do it in half the time now
All because of a nut...