Difficult cold start

MorganKane, I have exactly the same problem with my /6. Hard cold starts, even in warm weather.
Spraying Start pilot into the air filter helps a lot

I think that the problem comes from the fuel pump (in my case, it's the original one and it is 53 y.o.). It works to feed the carb, but I think that it doesn't prevent fuel to come back to the fuel tank when the engine isn't started for a long time.
So, the lines are empty, the fuel pump has to suck fuel from the tank and it takes time

IMO, the best solution : you (and I) have to change the fuel pump.

François