Kombi wiring

Well i have sorted some of it out but still a bit confussed as to the following

B wire comes out of a black cover tube. the black wire which is C goes onto Plus side of coil. I thought that B might have gone to Oil sensorer but there is another blue/green wire that comes out of black tube that goes to it.
Other than that i think all is well. do i need to have the choke wired in if so where do the wires go as i don't have anything that looks like wires for the choke

The pic is way to small for me to see what you have.
However, you need power to the plus side of the coil, with the neg side going to the distributer. For the chokes, run a wire from the plus side of the coil.

OK, your wiring colours don't quite match the circuit in the Gregories manual.

As per the manual:

Power cable to coil is black. That power lead (comes from from ignition switch) also powers the carby solenoids and chokes. There should also be a power lead from there through the fire wall (front LHS of engine bay) to the reverse switch on the GB (black cable). There should be an inline fuse in that cable.

Power cable to the oil pressure switch should be blue/green, the switch earths the oil light.

We found these leads so that's all fine.

The stray wire I guess is the switch for the heater fan. As per the manual it should be Brown/White though.
To confirm this, the switch to turn the fan on earths a power lead from the solenoid on the fan. So, connect a power lead through a test light to that cable. The light should be off. Next move the heater lever on the dash all the way down, this is the switch to turn the fan on. All being correct the test light should come on. If not either the switch for the fan is not working, or the cable does something else.

The solenoid for the heater fan as per the manual has the following cables connected to it:
Brown/White (switch as above)
Red, power from +ve on starter motor
Blue, from regulator (so fan only operates when engine is running). This is the same cable that should go to the alternator warning light.

Hope that helps and makes sense.

Also as I mentioned, check all you fuel lines and brass fittings in the carbs/fuel pump, the last thing you need is for one of them to leak. Send the fuel tank breathers to the air box, and keep an eye on your valve clearences!

Richard 😉