That one has discs, regular 26" seems a bit too modern for a pashley, let alone disc brakes, although that's what they look like. I'd get them and measure things if there's no clues left on the tyres, but I've only ever seen a couple of tyres so fucked you couldn't make out something useful.
Anyone know the wheel size of the traditional Pashley postie bikes? Someone I know has picked one up, older than this, and tubes/tyres are shot;
http://lovelybike.blogspot.com/2014/06/gone-postal.html
Say's 26" on here^, but the valves are Woods, so thought I would double-check...