Thanks for the interest and encouragement Michael 😊
Update: on Monday I fired it up with a remote fuel supply into the carbs and it ran well.
So I refitted the air box, reconnected the fuel lines, pump tank and filter but when I tried to start it yesterday there was a leak from one of the fuel lines. I'd used the original jubilee clip but using the correct fuel pipe fasteners cured it.
I managed to get it running again on all 4 cylinders and it ticks over as well.
The next problem is the indicators have packed up. This has already happened once and was fixed with a new correct spec relay. I'm guessing in putting it back together I've disturbed the wiring, the connections are not great so I'll need to trace that through again as the relay is under the left side panel which could have been affected when I refitted it