50's Olds guys a little help

50's Olds guys need some help
photo from a car show

I have these 3 pieces below - the holes are Larger then the Lug nuts
you can't mount the wheel covers

rusty stamped steel inner mounting piece - what is missing a tapered washer or a special lug nut or?


Here are my 53 Buick wire wheel covers below & heavy steel adapter
which has 3 smaller mounting holes at 11, 1 & 6 o'clock


Total of 4 pieces - you can see the 3 small holes that bolt the adapter to the rim

 

I think there is something that goes in the center and the lug nuts hold it on,I was trying to get a set for my 53 years ago but could only find one complete wheel cover and a extra center but none of the mounting parts. You might want to try Fusicks and see if they have the mounting parts.