Sorry, Noel, I should have said earlier that Silver Fox seem to do things in batches.
When I first contacted them about the Mk3's, they said that they'd get back to me, and they did so a few months later. I got the DVT and two suburban coaches from them.
A few months after that, they were doing another batch, and I got some more suburban coaches and some EGV's.
I contacted them late last year or early this year regarding some C Classes, and they have just finished that batch, now.
It's possible that they'll do suburban sets if there is enough demand, and they can allocate time to do a batch.
Still, if IRM or MM or IRMMM are going to sneakily release some Mk3's and DVT's, that solves that problem!