My new to me 1968 Motorola color set

[dieseljeep]

Originally Posted by zenithfan1

I worked a deal with Dwight Moody about 6 months ago or so, and I finally got it shipped to me when no other transport became available. It was well worth the wait. It works fine, just needs a few more tweaks to be ready for daily use.

Motorola built slightly different versions of that chassis for about four years running. TS914,918,921. Your's is the TS921, the last of the run.
Naturally, the first two runs used 23EG's. The last runs used a 25X or 25A type. The chassis was really reliable, the CRT's, not so.
40+ years ago, I installed a Zenith ChromaColor CRT in a set like yours. The original CRT was an Admiral, EIA 101.
The set owner said that the picture was good for about two years and went downhill fast.