Hello all, long time no speak.
Just a couple of points, I suspect cars have earth straps because of the heavy current drawn by the starter motor. Yes you will need to make sure there is good earth continuity across painted surfaces. It's true to say the bikes used the frame as an earth when new but this is largly a cost saving measure, it is a good idea when wiring a bike to incorporate an earth harness that conects components like the taillight and headlight directly to the battery. I'ts much better than relying on the frame.
As to the DKX distributor clips, yes they are a complete pain. Triton Thrasher's point about pressing the straight section of the clip with a screwdriver is quite right, it tends to bend out the hook end but if that fials try looping a piece of wire around the hook and pulling, that should open out the hook enough to clip it over, then you pull the wire back out of the clip.
Cheers Rick P
Has your Voskhod broke again? Suffering dodgy Italian electrics? Post your tales of woe here. Or ask odd questions about the rear wheel spacer on a Vincent Black Widow, should it take your fancy.