Thanks for the info all! Yeah it seems to have a bit of corrosion unfortunately; barn storage just doesn't seem to save things from rust in the Northeast. I'll be away from the bike until the end of the month but will strip the basic parts that I can do with allen wrenches and see how they clean up with some dish soap and report back! Will likely leave the freewheel / crank to a shop.
Would you try to acid bath the Guerciotti or leave it as is? I'm seeing one frame for sale on Ebay that someone restored professionally for $995. I'd hate to ruin what someone else could bring back to life, and something tells me that the acid bath is more a fresh start than an era correct restore.