Hi gatto,
Nice to see an English mortar here.
Attached is an original British Royal mortar. 5.5 inch calibre, cast in 1807 by John & Henry King for King George III. The bed is a Victorian era repro, it is of four layers of Oak glued together, the bolts don't go thru & it would not survive being fired, some of the iron work is fairly new. Unfortunately she must have spent too many years on display in a garrison or somesuch, the upper surface has been polished countless times removing a significant amount of material, the Royal Cypher being almost erased in the process.
Adrian.