It might be worth checking eBay?
I've done just that mate and sent emails to the seller's enquiring if the tiles were backed with adhesive (which I want to avoid). Thus far, no response. Still, it's early days
It might be worth widening your searches to model railway suppliers.
Great idea!!
I sometimes amaze myself as my mind obfuscates the obvious!
Thanks Ultravanillasmurf
. I'll get to it right now.