look closely and youll notice those arent the lugs on the outside, those are snaps, for a hubcap. the lugs are still where theyre supposed to be (in the center) but the weird snaps for a big cap kinda make an illusion. still no ideas.
Stock Buick wheels from the '50s. 69F100 is correct those bumps that look like lugs are clips for the hubcaps. Those look just like the wheels that my '58 Roadmaster had only painted red.
Both Buick and Cadillac had those weird kinda, sorta reversed wheels in the fifties to accomodate those dip dish full wheel covers. Caddys had them into the seventies I believe they are 5 on 5 like Olds, Chevy truck, some Mercs and Lincolns, I think they're a must if you want to run sombreros.
Buick used this style wheel center from the very late 30's thru about 1966. The rim width varied over time and by model. The widest of which were 6 1/2". They are riveted centers can easily be 'reversed' for an even deeper appearance. I recently took centers from from 6" wheels and put them into some new 8" hoops from Speedway. Interesting discovery I made in that project. The centers from 6 1/2" wheels are about an 1/8" smaller diameter (12 1/2") than the centers from 6" wheels (12 5/8"). The wheels rims from Speedway are 12 5/8". That's not all bad though, as the 6 1/2" are harder to find and I prefer not to 'sacrifice' them. Ray
Didn't Pontiac GPs in the 60s have the big bolt pattern? I don't remember seeing any steelies, the wheels I'm speaking of were mag or aluminum.
Look like stock Buick to me. Only Buick had this wheel 5on5" , the only wheel that small Buick hub caps will fit.
Pontiac and Olds used similar, but not quite the same, wheels in the period from at least '49 thru about '56 or maybe '57. They (P & O) if they had clips for poverty caps, usually had three clips versus the Buick's five. Pontiac/Olds/Buick/Cadillac all used the 5 on 5" bolt pattern for decades while Chevy was the 5 on 4 3/4" until the '71 models. Trucks were most commonly the 6 on 5 1/2" BC until they too were changed to 5 on 5". Ray