Can you elaborate a little more on the current situation.

Does the fuse blow when J2 is connected?
Are all the playfield lamps working now, with J2 unplugged?

Yes, with J2 unplugged the fuse does not blow and I have full GI lamps to the playfield and backbox. I thought perhaps I had the wrong lamp sockets in the coin door which I had refurbished over a year ago but I checked those and I've used the correct E-120-162 sockets. That's basically where I'm up to at the moment.