If you can't find any on the used market, or are in a hurry, Lamson probably has them. I've contacted Lamson about old style spools and they definitely have some old-style litespeed spools for sale, though a bit pricey IMHO, and I didn't ask about 3.5's. You might want to email them (they responded very quickly to me): info@waterworks-lamson.com Best of luck.