While I don't know for sure, I suspect they made far more than 500 90mm Angulons, and in any case the camera can be used with pretty much any small 90mm press style lens with just some shimming, shims to be included I think, and the job should be pretty easy with the ground glass they are including.

I happen to have a Linhof Angulon that I got years ago with my Tech III so I bought one of these almost right away, but even if I hadn't, I would have bought one. Keeping an eye out over the coming months would turn up something workable, I'm sure.