Want to Buy WTB: Lens board for Beseler 45m series enlarger, 42mm thread

I've got an older Schneider Componon-S with a 42mm thread I need to mount in my Beseler 45MX. The lens doesn't currently have a retaining ring, so I'd either need a threaded board or a board and a retaining ring (a.k.a. jam nut). Let me know if you have one lying around you'd be willing to part with. Thanks!