I sprayed some Gunscrubber around the tee piece and then tried tapping on the round end with a piece of dowel and a hammer. It finally opened!! I think the main problem was congealed grease. It's probably been a long while since this gun was last maintained.
I really appreciate the help and information I'm getting here. After I do a chamber cast I'd like to try and round up some ammunition. This gun is too nice not to shoot. I'll take and post some pictures as soon as I can.

The 2nd Amendment IS an unalienable right.