15x10 slot dish mags question

[musclcar]

just found a set of western 15x10 slot dish mags with 3-1/8th BS i couldn't not refuse and bought them.now here's the question these rims are a uni-lug bolt pattern that fit 5 on 4-1/2 and 5 on 4-3/4 and the do not have the washers for the lugs. were can i find these washers so i can mount these rims on my car could i use washer from the cragar s/s rims since they're uni-lug ??