Be sure and rig up some kind of filter on the auxiliary fuel tank, maybe might have to pull them..I would pull them anyhow and prevent any future trouble, re use what you can, the external tank will tell you if the center plenum seal leaks, if not then that is one less thing to worry about. I would at least clean it out and put new float needles and bowl gaskets..the old float needles aren't made for the alcohol they add to the current fuels, perhaps anything rubber inside the carbs and a good cleanout with air, clean the slides and vacuum caps, polish them and the manifolds while apart, then while off touch up the engine paint and polish the valve covers...check out sunnbobb`s polishing he does good work if your not up to it.
https://www.ngwclub.com/forum/viewtopic.php?f=6&t=44501
https://www.ngwclub.com/forum/viewtopic.php?f=6&t=44501