Update, went to Northampton Motorsport, luckily didn't spend too much time as diagnosed two issues.
1) The distributor curve is not right
2) The carb butterfly shaft bushes are shot and have a lot of movement
No point of continuing from there until I got these sorted. Carbs have been professionally rebuilt less than 2000 miles ago, including new teflon bushes. Not sure how it is possible to wear the out in 2000 miles but shall find out when I get the carbs off. Found a few other things not right on the carbs before, so a cautionary tale - be weary who you send the carbs for rebuild along with a 2000 dollar cheque for rebuild even if it is a reputable well known outfit. It worked out $1 per mile of use