New-to-me Sony Trinitron KV-1710

[Electronic M]

In 1954 color CRTs started at 15” then jumped to 19" then 21" round (which obsoleted the other 2 then was essentially the only color CRT for years). In 1958 Westinghouse had a 1 year only 23" rectangular that had convergence design flaws). For the 1965 model year the 23EGP22 came out and the 10-11" portacolor was introduced (and stayed till the late 70s), and the Japanese exported a 14" rectangular with a roundy gun. Shortly 25"/23V rectangular claimed dominance and Japan continued to introduce small screen color. Around 67-68 US makes introduced the 15NP22 in ~13-14" portables and I believe the in between 15, 17, 19 and 20 inch CRTs followed.
Japanese sets pre Trinitron are harder to follow because fewer survive, fewer people here seem to care about them, service literature coverage wasn't always comprehensive and they used mm for screen size designation in part numbers.