It seems your parents didn't give you one of those PlaySchool toddler toys in which you fit the shaped pieces into the shaped holes!
I think that's a very impressive "conversion" you did on this set. Mounting a rectangular CRT behind the round mask must have been a job. Looking at the picture, you'd never guess that was a modern set in that cabinet (unless one was there in person and witnessed the set coming on unusally fast).
I'd like to see a photo of the insides... if you don't mind. I'm sure it's not pretty, but would be interesting to see.
That's a very nice cabinet. Don't see too many General Electric roundies. Hopefully with some luck, you'll find the chassis that's supposed to go in there!