I agree with Andy... You'd need so much in the way of support circuitry, that you'd be better off buying a complete jig. And that little Trinitron tube might be worth enough on eBay (if it's in good shape), to go buy a nice complete 13 or 19 inch test jig
. That tube goes in all the 5" Sonys including the highly-collectable KV-5000.
Charles