Just to say I got this all sorted.
The pulley I got from shop4parts had a thinner inner section so I had to get shorter bolts. Needed a new tensioner also. Belt was a pig to get on. However I got a socket and bar on the tensioner and attached that to the front section of the car with some strong cable ties to keep the tension off. Then a ratchet to turn the crankshaft and finally got the belt on with a technique like putting a chain back on a bicycle.
Worth noting that I've had a judder when pulling away that I put down to the clutch being worn. Seems this has completely gone now the new pulley is on.