Eric;

You still haven't told us what kind of carbs you have...from your original balancing comment, I presume two (although I suppose one could "balance" a multi-throat single carb), but from the "brass mixture adjuster" it doesn't sound like SUs, which were the typically the carbs installed on factory export vehicles to the US, and therefore the ones I am most experience on.

If indeed SUs, then adjust three flats at a time, and take a test drive...if necessary, for a couple of days, including that cold-start... (this is a fairly small increment, but just big enough to be noticable), see also article: http://www.intelab.com/swem/checkchoke.htm , if other, like Zenith-Stromberg (egads!), then I'm sure someone else more experienced than I can help you. A book would help a lot and wouldn't be a bit expense...

Cheers