This gun sets off flags instantly.

Never heard of such an animal. Every 23 I've seen has the same safety as the 40's and 45's. However there used to be a company that sold an aftermarket tang safety for the Savage 99, I'm wondering if the old owner made it work in a 23?

If I had a pic of the stock I could probably narrow it down to another model, sounds like this gun was somebody's home project. Although the ealy 23C's came with a schnobel tipped stock the later models did have a squarer stock like the model 40's.