This is a hand built replica of the second version of the Mk1 Sten gun, this was the first attempt to simplify the production time, and reduce costs. The total Mk1 production was undertaken by Singers Manufacturing (Sewing machines) and they produced about a 100,000 or so Mk1's and Mk1* the latter being in very limited numbers. Most real Mk1's and Mk1* models where destroyed due to being obsolete, with some parts ending up in India sometime after WW2.
As to the replica it took ten years to finish due to lack of information, and many man hours work. The main reason is that the Mk1 and Mk1* have quite a few features which are unique to ether models, or in some cases are specific to one version only. Everything was scratch built except the magazine and the dust which are genuine. The rifle type sling is also Mk1 type and is made of a lighter weight webbing than that of the SMLE / No 4 rifle version.