You make a great point about the carriages. As you may be replacing the carriages, the below may be helpful to you. I used the dimensions for the trucks for a 32 pounder in this case, but the dimensions for whatever Bellona carried should be close to those on the chart below.
I would bet very few folks would notice but just in case this kind of thing is important to you, just as an FYI, The cannons do look nice but they look very much like the Bogard pattern guns which were used from 1716-1724 rather than the Armstrong Fredericks that came into use in 1760, same year as
Bellona. I have 2D and 3D drawings that I can email to you if this is of interest to you. Please feel free to PM me if this is of interest.
Allan
View attachment 590411
Page 1
View attachment 590409
Page 2
View attachment 590410
There were no doubt variations throughout the fleet, but lacking more precise information for
Bellona specifically, the charts should be useful.