65 'Cuda: Reverse thread wheels?!

yeah. The tire tech at the shop had no idea my 65 Cuda had reverse thread bolts, so he snapped one of 'em off my left rear wheel core before he did anything else.

I had to get on 'em to get it fixed, but they said the reverse sbp bolts were next to impossible to find. The solution: replace the bolts on my LEFT REAR WHEEL with RIGHT hand thread bolts instead of LEFTY bolts.
(no, I won't be going back to that shop)

OK..so now I just bought some 15 x 6 Cragars online, and I need lugs. NOW I'm hearing only the right hand side of the 65 'Cuda had right hand lugs..and the left had lefty threaded lugs. Is this true? the Newstalgia guy wasn't even sure.

I need to know how many of right and left threaded lugs to get..
(and btw..anyone know why did they created this weird reverse thread setup?)