First of all thanks for your years of service.
Parts for the C-dale headahocks are no longer made but there are a few places with old stock if you look hard enough. I believe the shock is some kind of elastomers and have limited life. No issues with road wheels on old mtbs as long as it fits. I actually know someone riding across the US right now on an old steel hardtail.
First of all, does the shock appear safe and free of excessive play?