Update,
I fixed the glow plug circuit so it now operates correctly - I'm sure the glow plugs are glowing - they were fine before installation, they draw a hefty current but don't blow the fuse.
I fitted a 100% straight to the car to eliminate the jump leads and the starter is slow, it definitely is from the petrol 1.5 golf.
It doesn't seem too slow, my old NA would fire even if the battery was so flat the motor would barely turn over.
I can't pull start it at the moment (no gearbox linkage!) The brakes need fluid and bleeding too. May get those jobs done and try it though.
After I had to return the battery to my next door neighbour, I checked the solenoid - I couldn't remove it from the pump but it clicked when powered - can I assume it is OK.
FINALLY..... I have a primer bulb fitted in the feed pipe, with the solenoid open, should the primer pump fuel through the pump and out the return?