This looks like a homemade or custom set, it looks like the entire cabinet was custom built, I can't imagine RCA made it, but it looks really well done...

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=200019984487

Notice the "built-in" radio... but it is an RCA radio.

I love that big red CRT!

Wow!! that's amazing!

Looks like it was based on the Berkshire cabinet: http://www.myvintagetv.com/rca_berkshire_regency.htm

I'm going to guess home made or custom job, lots of plywood in there and while the hardboard backs look nice there are no RCA stickers like you would expect to see.