Mystery solved!
The above cutlass was the only one I had ever seen marked to Apsam Co, London WC.
A recent communication from the Marine Museum in Chile revealed that they not only had boarding axes marked to Apsam but also had at least four of these cutlasses in various Chile museums. The cutlass is modelled on the British c1845 model and the axe is a close copy of the 1859 British boarding axe.
After independence Chile built up its navy and had many warships built in British yards during the 19th century. (more info here
https://www.boardingaxe.com/page21.html)
So it appears that Apsam was a company making private purchase weapons and also supplying arms to other navies.
Has anyone seen any other swords, cutlasses or axes marked to this company?