It seemed to me that when I took up the hobby of fixing discarded television sets from curbsides (circa 1978) that a TV repairman told me that the 23EGP was, in reality, a 21" tube! And that the tubes were made from the shells of dud 21" monochrome picture tubes (how did they ever get to add two inches to the claimed diagonal measure?).
Any truth to that?

This doesn't make sense.

1) Picture tube sizes were for a long time specified by outside diagonal. When the requirement for designation by viewable diagonal came in, designations added the letter "V," which was eventually dropped for new tubes when the tubes had been specified that way for some period of time.
2) I have read that the 23EGP22 envelope was based on a monochrome envelope design, but that does not mean it had no added features, was assembled in the same order or was made from duds.

Monochrome tubes could be complete assemblies of faceplate, funnel, and neck before the phosphor was applied. A color tube faceplate had to have locating details to mount the shadow mask in precisely the same location at least four times in a row: once for each color phosphor and then before mating the faceplate and mask to the funnel. So, there are details missing or confused in this story.

The process of removing and replacing the mask for each phosphor application is why monochrome rebuilds could include replacing the phosphor, but color tube rebuilds could not. Once the faceplate/mask assembly was fritted to the funnel, there was no removing it.

Thanks for the info.

23EGP22 data sheet can be found at
https://frank.pocnet.net/sheets/202/2/23EGP22.pdf

Outer diagonal is shown as 23 11/32, +3/23, -1/8;
Useful screen diagonal 22 3/8; useful width 19 7/32, useful height 15 3/8.

19.21875/15.375 = 1.25
Notice that this is narrower than the standard image aspect ratio of 1.3333...

This meant that the active trace time could be reduced from about 63.6-10.9 =52.7 microseconds to 49.4 microseconds, increasing the retrace time to 63.6 - 49.4 = 14.2 microseconds, which would crop the sides without geometric distortion of the image.

This increase in retrace time by 30% was very advantageous for reducing the peak voltage on the horizontal output transistor in solid state sets.

Most CRTs lost 2" from their designation after the 1968 screen size law. The 21FBP22 became a 19V##22, 25##P22s became 23V##P22s etc.

Did anyone from the Matsushita side even send a card or condolences?

I talked to two people that worked there!
Their recruiters used to haunt graduation day at MSOE, handing out invites to tour the plant and possibly apply for a position.
For factory positions, they generally hired relatives of other employees.
Both of these people said that practically everyone working there is related to another employee.

I wanna say 79 or 80.

I was gone then - moved to Zenith in 75. They Quasar, owned by Matshushita, not Motorola any longer, when you visited.