Dave,

Sorry, I can't help with the door gear. Sounds like you need something
on the commercial side?

I'm thinking now of using built-up doors: a timber or MDF framework covered
with some sort of lightweight sheeting, with bracing pieces where the
pictures will hang. This should enable me to use a fairly light-duty
running gear. The only question is what to use for the sheeting.

I think you might have baffled a few readers with your Asylum reference.

Hand is healing well, I've been lucky.

Glad to hear it. Last year I sliced through three fingertips with a Stanley
knife and got off lightly; one tip is still numb, though. I had to endure
the ambulance guys exchanging "Oh God, another DIY idiot" remarks...

Bert
http://www.bertcoules.co.uk