Shibby:
First, welcome to Videokarma. As to reliability, just what Andy said, especially his last paragraph. I own two Indextron's, both recapped by Andy. This was done 7 years ago. They both function well today.
The point I want to stress, congratulations, you have come into possession of a very rare television in terms of uniqueness and television history. If you don't already know, these sets are highly desired by collectors, the reason being, the Indextron was the first stand alone Index color consumer television. The Indextron paints a color picture with only one electron beam! See this link for more information.
https://visions4netjournal.com/indextron/
Edit: I have the complete service manual. It's yours for the asking.