Thanks for the replies, guys. I'll see if I can get a picture up tomorrow. I did some more digging and found the manufacturer's website - I was surprised they were still around! This particular knife was introduced in the 1930's as an electrician's knife apparently. They're made in Providence, Rhode Island. I mentioned it on another forum I belong to and someone said they had an old Colonial knife and sent it in to the company - they repaired it free of charge. Truth be told, every knife on their site says Lifetime Warranty below its picture. I sent them a letter and look forward to seeing what they have to say about it.
As far as leaving it as it is... I love old things. I do. I love the nicks and scratches in the bodies of my guitars. The "patina" of hard-driven vintage race cars. A few months ago I spotted a dark green 1934 Ford pickup with all kinds of stuff filling its bed, as it cruised down the road. I just smiled. It was a good, working truck.
My grandfather collected antiques. He had this big shop out behind the house. Giant armoire-sized music boxes, player pianos, cannons, gadgets... the guy's first car was a dual-cowl Dusenberg J. He liked his "stuff". He did all his own woodworking on the music boxes and bandwagons and all sorts of things. I think he'd like even something like this little pocketknife getting a second chance. Is it an heirloom or a tool? Without a doubt, it's both. I'm 24 now, a long way from having any kids, but as soon as I had this Colonial in my hand, it was very easy to think of it going to my son someday, too. It's a nice thought, anyway.
I'll keep you posted!