All good. I find the history to be quite fascinating but can also understand why there is much confusion / frustration.

I did learn (thanks to everyone who replied), that I have some type of 1200TX or variant, originally and still chambered in 30-06 and was built ~1970. The proof marking are legit and now I have a base solution (again thats to thread contributors) on the way...just got shipment notification. With any luck the rifle will be ready by the weekend. Cant wait.

I guess the confusion will just need to add to the charm...always look for the positives!

Cheers.