In reply to MichaelGallimore:
Hi Michael, the short answer is that you can't buy rubber in the UK without being an established resoler.
I have just started up resoling based in Llanberis (Llanberis Resoles) and getting rubber was pretty difficult for me. You can only buy direct from the distributors for which you need a trade account with them, on top of that rubber (sole or rand) is sold in full sheets a bit under a meter square (and a sheet costs more than any new pair of boots!), then there is getting the right glue, primer, sander etc.
More to the point resoling is pretty tricky, I went through at least 10 junk pairs of shoes and a full sheet of rubber before I started producing a reasonable finish!
If that doesn't put you off then send me an email and next time I get a new order of rubber in I'll see if I can spare some.
Hope that helps. Otherwise i'm doing a cheap start-up price on resoles until the end of the month!