Clutch... Now you see it, Now you don't and Back

[BAT]

I am new to the '60 - '66 trucks and have my first '66. It's has a IN6 with 3 on the tree and has been sitting in a barn for the past 25 years. I now have the engine running like a fine tuned machine and just need to fix a pin hole in a brake line and will be ready to try it on the road.

So the other day I slowly drove it from where it is sitting in to the shop with no issues. Tried 1st and reverse and both worked perfectly. All I did was try to fill the master cylinder and located the brake line leak and nothing else. When I went to move it back to where it was I had no clutch what so ever. I ran out of time so we pushed it back to where it was and left it assuming that the clutch just went out.

Last night was was tinkering in the shop and decided to go out and see how my '66 was doing. She started right up and now I have clutch?!? WTF?!? I don't know a lot about clutches and am no mechanic but I can tackle just about anything with a little research direction. Any suggestions on what to check? I was thinking that I need a new clutch but don't want to spend the time and money if there is something else I should be checking first.

Thanks in advance, you guys are awesome!!!

BAT