Vw transporter

If you can get inside (it's not hard and you won't need to break anything), remove the sliding door handle (one screw from inside) and there's a 4 digit code on there, which is the code for the key. A good locksmith on ebay will be able to make a key to this code.
(or I can pass you someones details on if you struggle)

It might not work great because the lock and key wear together, but see how you go. I had a key cut to code, and it only just barely worked.

Try not to damage any locks if you can avoid it, especially if it's a matching set - another matching lock set will cost you £150+.

AFAIK mk2 golf ignition barrels fit, but the door locks are t25 only. I've got a pair of front door handles (on one key) if you need them.