The No1 MkV trials rifle, 1922-1924, was an interesting but ultimately unsuccessful attempt to make up for shortcomings in the No1 Mk3. About 20,000 were made and sent out to troops for trials. These days they show up in all sorts of places and many, once sporterized, have been restored. EFD.com are reproducing No1 MkV front bands, rear sights and top wood. A well known picture on the internet shows one of these in use during the Viet Nam war.
The improvements consisted of an extra band attached to the nosecap to strengthen the front end, possibly to improve accuracy by stiffening the wood area, and also to strengthen this area for bayonet fighting.
The sight axis was lengthened by moving the sight as far rearward as possible, and an aperture type rear sight was created. It suffered by being vulnerable to damage through too light construction, and the sight bar not remaining locked in the range position during recoil.