For the ballast, fish tank gravel is available in many sizes and colours from aquarium shops. Cheap too.
Would be great to see also your work on the section - Please start a building log of yoursSlowly but surely, spent a couple of weeks doing just the barrels, should have done that in a better ventilated area, accidental glue sniffing occurred, not pleasant. You are way ahead of where I am at, just starting to do the interior fitting of the bottom deck.
Maybe my next build. Me doing a log of the Bonhomme Richard section would more be a litany of errors. The lastest of which was me wondering why the shot locker didn't fit under the bottom decks cross beams. It was only after I adjusted part D31 to move one of the beams that I noticed faint laser marks on the side of said part showing the correct position of the beams.Would be great to see also your work on the section - Please start a building log of yours