I've got bored out VM26's on my J and tank wouldn't seat because the original tap hits the carbs top. Had to make a feed plate and run an inline fuel tap. Anything can be made to fit.

Z1000j series.

If you need VM26's I've got a really good set spare.

If the old battery was also a gel battery when they get drained below a certain point you can recharge to show good volts but often they can no longer supply the amps required.

Wemoto doh, webike.

Why are you buying a battery from Japan. Tayna.co.uk is the go to UK supplier for motobatt. 1 or 2 day delivery time. https://www.tayna.co.uk/car-batteries/?gad_source=1&gad_campaignid=11322118469&gclid=Cj0KCQjwzOvEBhDVARIsADHfJJTu6ZgJhIAJe42Ekgh7PwcR9hb34nKavpONTr_sasriPu904C6vr38aAvhKEALw_...

Yes it is possible for twin coil to fail in one side only. The wires inside have to split into a Y to to the two ht leads. I seen it a couple of times on hard wired coils where the ht lead can't be replaced (easily). Your coils have changeable ht leads. It could just be the dead ht lead wasn't pushe...

Pretty much any engineering workshop can make them if you can't yourself. Just need to give them drawings.

Make adapter plates

If its just had a total engine rebuild having been rebore, new ring, honing etc the assembly lube burning off and rings bedding in until it clears completely. Black Plugs. Which make/grade plugs? If they are BR#ES then they have a resistor in the plug. If you also have resistors in the caps you'll g...

Be careful which colour restorer you use i think it was back to black i tried and it fetched the decals off. Back to black is not a colour restorer it's basically a solvent that dissolves a very fine layer of the plastics. Colour restorer is a ultra fine t cut type liquid. T cut is super abrasive c...

Autoglym colour restorer is the easiest way to do it. I use it for all the old faded black plastics.
2000 wet n dry to take the surface bloom off then polish with colour restorer.
You well get high gloss black shiny as a shiny thing so if your not after that ignore me

Hhhmmmm, which manual to believe, fsm or the the dandy.

Sounds like you have them set perfectly for ethanol laced fuels.
Dark tan on the earth strap blending to black as it curves to the plug body then black on the plug base with the core insulator the same dark tan again.

Plug caps and plugs both have resistors resulting in weak spark sooting the plugs at low revs.
At higher revs your getting a better cleaner spark due to increased charge voltage.......
Maybe? One or no resistor/s per ignition line only.