Hi Peter, thanks for posting....
The choke is physically sticking but as you say, my assumption that it is the cable could be incorrect, it could be the actual carbs sticking. I will look into this when I take the carbs off.
Regarding the idle speed, I can sometimes get it to slow down by pulling down on the accelerator cable but it doesn't always work but again you have given me some things to look into.
I am doing the 2019 France RBRR next year, so I will fit a heat-shield, I think it would be prudent.
When the weather turns (still enjoying blasting down the country lanes with the roof down), I will strip everything down, so your comments are very helpful .
Cheers....Derek