060 on block and pistons

[Slik]

Working on "unsticking" my "barn find" engine in a 29 150A. Prior to it being stored 30 years ago all the values, springs and guides were replaced. The car was driven maybe 250 miles after the valve work then put in storage.
First day - I tried using the hand crank to turn the engine - nothing.
Shot 2 cans of PB blaster down the plug holes and trailered it home. Back passenger wheel is locked up - made it a bit of a bitch to get off the trailer, but she is tucked away in the garage now.

I've begun breaking it down and bathing it in MMO. Pulled the head and surprisingly other then just a bit of carbon the values and piston tops look almost like new. As i wiped the little bit of grime from the piston tops I noticed 60 stamped on them - I also found the 060 stamped on the back part of the block. I'm taking a guess here but I'm thinking that is saying this has been honed to .060 over ?
I've removed all of the values, springs and guides - numbered them and was planning on using them again. Not trying to be cheap but can I clean up the outside cone end of the guides - they have a bit of rust on them - and reuse them ?
Drained radiator and gas.
Pulled the oil pan and there was some sludge in it - removed with a putty knife.
Next step is to seal all orifices and flood with ATM and Acetone mix and let it sit for 4 weeks (while I'm on travel for work). Hoping when I get back that maybe I'll have some movement in the engine.
Reason I was asking about the 060 number was that IF I get to the point of a rebuild I guess I'd need to determine what size piston and rings will be needed.
I'm told this is the original engine and it has 69830 original miles.

Glad I found these forum - only downfall is that I'm spending more time on here reading then getting other things done - like cutting my grass