Thay are 14's, I don't have any 15" slotted wheels but I know where I could get some if I needed. Thanks for reminding me of them

I may need them for my new project.
Anyway the sloted wheels are pretty easy to come by. Try swap meets or even garage sales. You do have 5 on 4-1/2" bolt circle don't ya. What do you want them for? The 15" wheel say like on the duster in your pic wouldn't fit very well or at all with any descent sized tire. The 5 on 4" BC are kinda hard to find. Let me know if I can help.