Thanks Bandersnatch, I use KBC regularly, good tools good prices, but as you say cone drills are not there.
NDIY, thanks, know Lee Valley well, we have one of their stores nearby, but they also do not carry cone drills.
I emailed Screwfix and unfortunately they do not deliver to Canada.
I can get a too-large one as part of a 4 pc set of other drill types from China but can't yet find the 3 pc set Mike showed from other firms there, or individual ones.
I think I'll just make my own, it will probably take less time than searching searching searching on the web. I'm familiar with the design of these tools – did many for machining heating valve bodies on multi spindle machines 30 odd years ago at work. Wish I had the old Japax wire EDM I used to use for doing them in brazed carbide to a mild steel turned shank. The shank provided a nice datum with sturdy rigid support and the EDM made perfect relieved profiles very accurately. Carbide stood up well to sand cast bronze and forged brass. Just some tool nostalgia….