Took apart all of the nonsense to get to the heating/cooling control apparatus so that I might replace the two tubular bulbs that are out.
Tried to replace them with 74's, but even before installation, it seemed that the bases were a little too wide. Attempts at installation were unsuccessful, and aggravating.
Both here, at the Sylvania website, as-well-as in a few different auto parts store databases - they all list the same, "74".
wtfing-f
I'm on the verge of applying a dab of dielectric grease so that I may, "Massage" them in.
So, am I high on smoke, or are these new(er than 20 years ago) bulbs too wide at the base to fit into the socket of the heater control panel that illuminates the midsection of the array?

I found two other types of similarly shaped tubular bulbs that I thought would fit, but had different volt & watt requirements - any thoughts about using those instead?

 

Damn - the 74 vintage worked. It didn't look pretty, didn't break anything visible, coated the hell out of the contact points with dielectric grease and jammed those little bastards into their new home.
Now if I could just make this thread disappear..