Thank you for the reply.

The engine that is fitted to them would be helpful, as would anything to do with the transmission.

I purchased it knowing that when cold it required a lot of revving to move it until it warmed up, then it drives much better.

There's a dipstick/cap for the hydraulic oil on the left hand side under the engine cover (right on the mark), i've no idea if this is also the level for the transmission.

When cold it moves like you would expect a manual car to move with a very worn, slipping clutch.

I'm hoping it's something as simple as low transmission fluid, blocked filter or maybe badly adjusted inching pedal, so any information / diagrams on the transmission would be of great help.

Not sure if it's relevant, but the previous owner also told me that when it's been parked up overnught, it drops a small puddle of oil, he told me it's been like this for the whole of the 15 years he owned it, it was just used to lift engines in and out of vans, so he never bothered to do anything with it.