Try contacting Jim Steck for rims too, he's got an adjustable rim rolling machine. I was going to have him build rims for a D.VII , but I don't want to foot the bill for another custom tire batch. He's already made D.VII rims (Dick Enos') and still has the tooling. (His main business is restoring and scratch building antique Alfa Romeos). I ended up with original barn fresh 1928 21" Ford Model A rims ($30 each!), which I'll respoke to my own hubs. And, high pressure, non-clincher Model A tires are real cheap from Coker Tyre. He can make any size though, just give him the specs.
Jim Steck's web site.......
Alfa Romeo Performance Engines
For custom spokes (and rim drilling if you need it, from drawings or your parts), try BUCHANAN'S Spoke and Rim Company. They've been around since the early 1970's, and are VERY reasonably priced.
Buchanan's web site........
Buchanan Spoke and Rim, Inc.
.............................................Pete