If you have been following the build of the model Armstrong cannon, you might remember that most of the steel panels for the carriage were laser cut a few months ago. In the past few days I have been drilling dozens of 2mm holes, ready for final riveting. Meanwhile the parts are held together with 2mm bolts and nuts. I expect that the rivets will not be installed until I can see that everything fits and works as it should.
SWMBO’s comment…. “It looks like it is made from Meccano”. I guess that there are a lot of holes.
Meanwhile I have discovered an excellent reference source, published in 1879. It is a free book, available online at Google Books. “Treatise on the Construction and Manufacture of Ordnance in the British Service”. 517 pages. Original price 9 shillings. It is full of gems for the cannon modeller. As an example, this is a drawing of the sights on the 64 pounder RML converted to 80 pounder. You will see that the barrel shape is different from the one which I am modelling, which is a mark 3. But it is probable that the sights remained the same as those pictured. A great find, with enough detail for me to scale down and model.