I too had an ME Super until it got drowned during one particularly wet Goodwood festival of speed.

The lenses will work on the DSLRs but with limitations. Obviously you lose autofocus and if they don't have the A setting on the aperture even metering for exposure becomes a bit of a chore. That will be a pain for an everyday lens, added to the fact that the zoom range of that 28-70 won't be as useful on an APS-C sized sensor. But, for a nice telephoto lens, for example, you can live with these issues. I often find myself using my old 28mm and 50mm primes as well. They just do away with that "taken with a kit lens" feel.
Pentax DSLRs don't generally have many friends amongst reviewers but I happen to like them. Early ones had pretty poor AF systems compared to the competition but the latest such as the K5 and Kr are good enough. Aside from that I don't think there's anything else that's poor on them, and they have some nice features such as image stabilisation in the body.
What they do get right are the ergonomics. I just get on better with a Pentax body than anything else I've tried. Anything you want to tweak is at your finger tips without taking your eye off the viewfinder.
I think their prices are pretty good value for money, too, and "semi pro quality weather resistant body" doesn't mean a chunky great thing to carry around, either. I've spent enough time comparing my K7 with my dad's EOS7D to know what I'd spend my money on if I had my time again.
Anyway, I reckon there's pretty strong demand at the moment for old Pentax lenses, especially primes. You'll make £50+ for a 28mm / 50mm manual focus prime. Less so a Tokina zoom. I suspect the mirror lens will be a bit lacking in quality these days but someone'll buy it to play with.
Have a look on the Pentax User forum to gauge interest..
http://www.pentaxuser.co.uk/forum In particular the "Lenses for Pentax Cameras" and "Classified Adverts" sections.
