You're cat sure does like you. Usually they only bring home dead mice.
Congratulations on the new set. I agree that the tuner modification was done very neatly. It's too bad from an originality standpoint that it was done, but it is part of its living history. Leaving it in place helps to tell the story of that particular set, taking it out helps to tell the story of that model. Do you know anything about the set's past or original owners?
If the set uses the same rubber CRT mask as the TRK-12 (I can't imagine it doesn't, but others might be able to confirm) you can get a reproduction for your set. If you look about a third of the way down this page you'll see it listed
http://www.earlytelevision.org/class..._for_sale.html