having become a Trekker in the 1970's I'm well aware of the limited availability of visual reference materials but at conventions (which FJ also visited) we bought and traded prints from film stills or - where necessary - pictures taken from our TV sets. This may have been crude compared to today's standards but it wasn't rocket science. You just had to put some "passion" into it.
Of course, exotic sets had less feature time than in comparison a set like the transporter room. But given the regular appearance of the transporter room in the series it was obvious that the odd angle the console had in the studio set drawing in The Making of Star Trek
was wrong, yet it reflects in FJ's works with the same angle. Did he understand that the function was to control and face the transport chamber?
Apparently, he didn't care to check or notice.
And the same story obviously applies to his reproduction of the type II phaser. The photo illustration section in The Making of Star Trek
has several discrepancies but the most noticable (and in this context tragic) one is a photo cut-out of this phaser which altered its form.
And that's obviously the reason why it has the incorrect shape that FJ reproduced in the TM.
Ironically, the phaser is among the items which according to the interviews started the whole project and yet, it seems he never bothered to take another look at a picture of one of these at conventions or elsewhere.
Since he made it abundantly clear in his interviews how dispassionate he felt about Star Trek, these (or other) things don't come as big surprises.
But what amazes me in this thread is the myth building as if he had the great masterplan to unlock the mysteries the creators themselves were not aware of.