I was recently given a 1948 HG42. I'm just beginning to find out about it, and would appreciate any help that's out there. I guess my first question would be "What is the difference between an OC3, and an HG42?" Secondly, does 34GA478 sound like a correct serial number?
Welcome aboard!
If you do a search of this forum, you will learn quite a bit about your crawler.
There are a lot of experts who can tell you the differences between the two. Hopefully one of them will answer in.