Has anyone considered that it might not be timing at all?
Given that the bike was supposedly running well prior to this happening, I'd suspect a breakdown in the armature winding rather than timing.
I've experienced two K2F failures due to this, and both times, when removed from the engine and grounded against the cylinder heads, the sparkplugs produced what seemed to be an adequate spark, yet installed in the engine, the best it would do is fire up and idle for a few seconds. As soon as any attempt was made to actually get usable power from the engine, it would quit running.
Regarding the "manual advance" version of the K2F (the one that just failed in my Interceptor was one of this type), the default position of these (assuming the pawl and spring are in place) would be full advance. If the Pawl and spring are missing, it's anyone's guess where the camring is going to be positioned.
The lever pulls the pawl out against the spring pressure, pulling a notch in the cam ring and rotating it to a retarded position. Moving the lever back allows the spring to push the pawl and camring back to the advanced position.
I'm still in the process of converting my Mk1 Interceptor to distributor and points ignition, borrowing the Lucas distributor from my Indian Tomahawk, which probably won't be needing it for another year.
In the meantime, I'll be looking for a more permanent solution, possibly the BTH magneto you guys are talking about.