there probably weren't, but I don't hv a tally of which ones did or didn't. it's on the Factory Optional Equipment list.
wouldn't an avionics shop doing all these new fancy updated panels add that?
Ken Levins has a good plan fm another topic:
https://hoster3.commander.org/vb/forum/members-only-forums/refurbishment-paint-interior-upgrading/161006-new-eyeball-vent-in-panel
93W must hv changed out to single pane glass; Hoover clip showing dbl. pane. it's the 6th fm last '77 produced. didn't know Rockwell started the dbl. pane before the '78's. always thought dbl. pane was only '78s and '79s. : ]
hard to make certain w/just a 4 and a Whiskey showing.. none w/that # registered in Lacon, except N4931W, Clifton Perry.
that partial on your pic looks like a 4 not a 1, tho.