Reading your post, your basically getting everything right and are in the "right' place with mostly everything. Word of advise, put some black tape over that darn AFR gauge especially at cold idle startup!! Trust me, I have 3 complete O2 AFR kits I use to tune race engines/customer cars, and no less than 10, yes 10 oxygen bungs on my own personal car!! it will drive you nuts lol. A carb'd engine will smell "rich", especially without cats, some more than others, cam overlap,timing and heads play a part, and play havoc with you and the AFR gauge. Once your good at idle, take "note" of the AFR gauge to give you your baseline, that's it, do not tune to a predetermined AFR #!! A "cold start" tip I tell all my customers with my custom built (no choke)carbs/engines, few good pumps, start it up, keep you foot in it for 2-3 minutes at 1,500 rpm or so, and shut it down for 5 minutes to heat soak. Fire it back up, the heat will get into the pistons (especially 2618's) valve springs, and put some heat into the intake, you need heat to vaporize the fuel. I'm North of you, and have a few customers who drive there cars late, but there is a limit to driving in the cold, especially without heat crossover in the intake, that's what your experiencing. Wait till next spring/summer, it will change, for the better, and you will not need a choke.