I just finished restoring a fine 4C from '37. (built between 33 and 65) Purchased as a parts gun for $70 with no bolt. Bluing was perfect with a minor bit of hazing some steel wool took care of. Bore was perfect however with some dry firing pin damage for which I stoned out. Placed and ad here for a bolt and to my joy a response from NB saved the day. Total all in $150.
I have Williams FP peep sights attached to the original mounting holes. If you are considering it, have a smith drill and tap for a target peep and never look back. Mine shoots like a dream and I must say they knew what they were doing back then.
Take a look at the back side of the butt plate, a date may be stamped on it indicating the date of manufacture. I finished mine with 50/50 Boiled linseed varsol (2 coats) and must say, much finer finish than that of the original. I would recommend an oil finish for that old walnut stock. Bed 1.5" front and back of the mounting slot and inside the slot using JB. You will find this greatly improves the accuracy around all types of ammo, but mine clearly prefers CCI standard (sub half inch at 25m with open sights no less. Very impressive for an 80 year old rifle.)
When you find some checkering tools, follow the original lines closely. Slow and light passes will quickly show you what you have. Will give you an appreciation of the craftsmanship held from yesteryear.
Give that old bolt a bath in varsol for a couple days and clean it out well. They gather a lot of crud over the decades. I also stoned the sear in order to get better purchase on the bolt. If you are having some problems with cocking and falling off have a look at the little screw that stops the sear, it allows for some travel to adjust the sear engagement. Mine was too long so I filed it ever so slightly until perfect. Mine breaks clean with a surprisingly nice trigger pull.
Cold blue works ok but will wear faster than the original blue. Perhaps a coating of choice would protect it forever. Enjoy the restoration, they are well worth it. A bit of nostalgia to bring to the range and place the competition in their place.
Elky.