I'd consider making a donation to the KWVR if they promise NOT to get a Pacer!
The problem with keeping the preserved first generation DMUs running is getting parts. I read recently that the cost for a single refurbished axle for a heritage DMU is about £10k.
Pacers are just as much part of railway history and several should be preserved as runners on heritage railways. They are a cheap to operate unit for a heritage railway. Many of the younger generation won't remember Class 25s, 304s, 504s, 104s, 108, 115s etc.
It is just the same with vintage bus rallies. I don't consider a lot of the buses that are at the rallies vintage and vehicles such as Dennis Dart SLFs are just too modern for me. My idea of vintage vehicles are Leyland Titan PDs, Daimler Fleetlines, AEC Routemasters etc , though the younger generation won't remember these in service,