Just completed this. The only difficult part is pulling the control unit out far enough to access the bulbs. It is kind of trapped behind the dash frame a bit.
Two of my three were out, but I had a bunch of these bulbs in the garage from some other cluster I took apart or something, i don't remember. The ashtray uses the same bulb as well. I do not know what number they might be at the parts store. The ones I put in said "74" on them. Might be the number. They are rated 14V 1.4 W. The bulb for the lever panel right below was out too, so did that one as well. Guess I will see tonight how they work.