Very hard to start after a few miles.

[Nambo]

Which is what Roger is saying, when the starter is engaged with the key, the feed is allowed up to the coil to bypass the ballast. However with the way you have connected it, the coil feed will now be trying to pull in the solenoid as well when the ignition on. This is because the coil is getting it's feed but so is the starter solenoid when it shouldn't be.

Ian.

Oh of course, my apologies, the electricity will now be able to run back down that wire from the coil to power the solenoid even when the starter isn't engaged.
Looks like the starter has to come off after all!

[Nambo]

So I took the solenoid off and a local auto electrical shop fitted a new end cap, £20 all in!
I then got my 12v feed when turning the starter motor.
It was only today I finally took it out on the road for a few miles to get it nice and hot.
Within 2 miles of home I saw a lovely blue Stag and then a parked up nice brown one at Westerham.

When I got home I turned it off for a few minutes, then tried starting it again, started instantly.
Left it for 45 minutes and tried again, once again instant starting so looks like that additional 12v feed has made all the difference.

Pete