here's another question. my 61 half ton GMC is at least now a very plain jane version. no chrome or extras. the heater control housing though having 4 slots only has the fan and defroster levers and the outside 2 appear to be blanked off. I can get by fine with that as I can install a valve in the heater hose to just shut the flow off during the summer once I get my new core in and get the heater back in. but there are 2 round holes in the dash one above the other about an inch in diameter between the heater control and the glove compartment. they appear to be factory made and nothing in them.does anyone know what they might be there for? I need to find a couple of snap in plugs to fill them I guess. ordered a new seat cover today and very anxious to get the seat back in so I can get it on the road. Raymond