I'll second Riesel and Whilton's for 2nd hand gear. Riesel would be my first pick: more variety, better prices. Get hold of the yellow cover phto advertising magazine (can't remember the name), they advertise their range there.
Grace's was still there when I visited last year, haven't been back recently. Was way over-priced back then but had some interesting older gear. Didn't haggle with the bloke - that might be an option?
Vanbar is more for chemicals and new gear, wasn't aware they had old stuff.
Mainline has it all on the website, check it there. Sometimes they put items on ebay, worth a check just in case.
And that's about it, I guess?