I am sure there are people with better responses to give than mine, but I will say that 4 5/8 is very likely a 12pdr (4.62" bore), 3 and 6/8 is probably a 6pdr which would have a 3.67" bore new, 5 5/8 is very close to the diameter of a 24pdr shot of 5.68" although the cannon bore is a bit larger. 4.5" is 0.02" off the diameter of a 12pdr shot so probably a 12pdr. In the few records I have looked at, folks seem to SWAG the bore diameters of guns quite frequently.