Dear John
Please contact me off-line and we can discuss this further. I have produced for NGA Archive a series of scale plans based upon contemporary French and German plans of British Ordnance.

As you realise that I have a large collection of plans. Gradually these will be made available in books but they are available through NGA Archive in the meantime. Some have been used to illustrate Issue 1 and 2 of the Smoothbore Ordnance Journal that will be published in hard copy format by Ken Trotman. There is planned to be an issue that will be mainly upon British Ordnance and I am awaiting a number of contributions to put that together.

The lack of plans in the Royal Artillery Library is a great concern. They are there and have not been recognised or destroyed. Alas I have not been permitted to look and the collections are not catalogued.

Franklins Book is excellent but he has based his lovely drawings on the 1846 drawings and had not realised the significance of having no following machines etc... As you know better than me that cutting curves with hand tools of the time is very difficult. Carriages were rather crude in construction when you can see an original. They are very rare.

Main differences in the block trail were the wheels, hubs, the flattened rather than rounded end to the backet and just before the elecating screw. The barrels did not change drastically over the period. The technology used to construct carriages changed from the 1800 to 1850s.

There is still much to try and sort out.

Stephen