I wouldn't order anything yet. The color on 1/3 is promising. Lets try to adjust out the lean-ness with correct fuel levels and changes in mixture screw.
As you indicated, get the fuel levels correct on all float bowls, then, do an idle chop with all mixture screws as they are right now, with brand new plugs...5 minute idle w a box fan on the front case.
Report back with a picture of all four plugs in a row, we need a closeup of the white insulator (not a side-on picture) so tip the end of the plug towards the camera. And as a help to us so we don't have to read backwards to find 'current' settings, include your carb and plug chop specifics for that test with the pics.
Its helpful be able to see the effect of your changes, from chop to chop....
(i.e. idle rpm plug chop, 38/105 jets, screws 1.0 out)