I looked at the pictures on the other post and the mum was cancelled out as is customary when taken out of service and used as a school trainer. Once cancelled, it’s not as collectible as a full mum’d rifle.

Depends on the collector but some will take a ground mum over a trainer as ground meant it was still in survive at the surrender. A cancelled trainer can still be shot if if it’s serviceable but again...it depends on the collector.