I don't quite understand the persistence of the question about whether they would be made to exactly match the weight of the old floats. The weight of the floats is immaterial. If the floats weigh more, it's fine -- as long as the manufacturer correctly designed them for the correct displacement and the placement of the pin. The old floats have a maximum weight based on their exact size, density, and where the pin is located. Floats made with a slightly different size, shape, material, etc. can have a different weight and still function the same.
RV-12 # 222 N980KM "Screamin' Canary" (bought flying)
Fisher Celebrity (under construction)
Previous RV-7 project (sold)