Old 26" Bike Tyres (Twickenham TW1)

I need a couple of old 26" tyres for a bike I'm restoring. It doesn't matter if they're worn out, as long as they're still in one piece. (If you're about to replace a worn tyre with a new one, rather than throwing the old one away, I can take it - it'll be good enough for what I want). Thanks.