Pete,
T35 Dougs are probably the easiest of bikes to start - it is not unusual to be able to operate the kickstart by hand!
With regard to the plug leads - Lucas magnetos run happiest with copper wire HT leads and non-suppressed plug caps.
I don't have the choke slides fitted to any of my carbs - they are more trouble than they are worth. They are awkward to operate when under way, and become worn enough to fall apart. I have fitted carb tops for use with cable chokes and then fitted screwed blanking plugs in the choke holes. With them correctly set, you should only need to tickle the carbs when starting a cold motor - once the engine is warmed up, it should start and run without any enrichment of the mixture. As you are having problems with the tickover, it would pay to strip the carbs. Press out the brass choke blocks and check out the drillings on the engine side of the blocks. You will find a shallow drilling about 4mm dia - in the bottom of this drilling there is a much smaller drilling (about .75mm) - this is the fuel jet for the slow running mixture, and often gets blocked.
Hope some of this helps,
Regards,
Eddie.