Colin,
If you have Dragonfly pistons, they will be split skirt pistons with slots beneath the ring land. The rings will be 1/16" wide top ring, 3/32" wide stepped compression ring, and a 5/32" wide slotted scraper. There are known problems with these pistons - if the engine is worked hard for prolonged periods, the crown of the piston starts to collapse into the slot, resulting in the grooves for the rings taking on a wavy form - thus tending to trap the rings. However, they have the same crown design and compression ratio as the Mark type pistons, so will not require any other changes to carb settings, etc.
With regard to the O/S cylinder smoking on tickover, I would double check that the carbs are correctly balanced - the poor balance may be resulting in that cylinder not doing enough work to keep the oil back. Try easing back the cable adjustment on the LH carb so that the RH cylinder does a little more work and see if that improves matters.
Regards,
Eddie.