I use Fuller exclusively. It must be mixed perfectly or it will dry too hard and yield tiny checks or too soft and get gooey and milky in humidity. It is very misunderstood.
In my use, i found thunderbird to be inferior and does not hold up well vs. Fuller. It also yields tiny white spots if the spraying conditios are not perfect (70 deg. and 70% humidity).
I use a HVLP touch up spray gun by Devillbis with .08 mm nozzle. The mix shouldbe 16 parts fuller to 1 part catalyst and 1- 1 1/2 parts laq. thinner ..medium dry.
use a cocktail shot measure one side is 1 oz. the other is 1/2 oz. You vcan mix up 16oz. or 8 oz of Fuller in picjkel jars depending on the amount you will be spraying. also be warned..2 week shelf life, keep it out of direct light when mixed, and when not in use, refrigerate to slow the chemical breakdown once mixed.