Chrysler 5th Avenue Rims

I have a 1986 Chrysler 5th Avenue. Yesterday I bought new tires and
the extenders from the rim to attach the hubcaps are of different
lengths. Short ones on the rear and longer ones on the front. The tire
folks said the rims in the front are different than the rear rims. I
don't know which ones are correct. The rear rims did have studded snow
tires so I think the previous owner simply had his regular tires on
original rims and put the snow tires on other rims. But then where did
he get the different extenders?

Since snow tires are not a consideration in S AZ I would like to know
how to determine which rims are correct and where to get different
extenders.

Thanks
Bob AZ