Commer Express Delivery van: why so rare?

[Jukebag]

Anyone know why Commer Express Delivery Vans from the 1950s (not the camper vans) seem to have become very rare among the classic vans and cars that are still in relatively good numbers today?. They were similar to a Ford Thames van and somewhat similar to a Morris Minor, but where those two are still knocking about (particularly the Minor), the Commer Express vans have pretty much vanished off the face of the earth.

I don't know how popular or common they were back in the 50s and 60s, but my dad owned two during the 60s and knew one or two other people who owned one.

It's ashame very few of them have survived and haven't been preserved by enthusiasts.

Found this one for sale:

http://www.carandclassic.co.uk/car/C829591