[clay68c10]

Very cool, remonds me of the stuff I used to see in fields when I lived in Wyoming. You have got a keeper for sure!! Mine truck is similar, except for that #'s matching engine thing .... I also have a choke delete, but it is a plain round bezel screw with a plate behind it to block the "choke" word on the gauge cluster. The square GM type is the one I've seen the most. Anyone know more about that...?
Definitely check the cowl and the kick panel vents. It's amazing how much funk can accumulate in there.