Updated: Jan 20
If you are lucky enough to have an unmolested No4 mk1T, then you could have a rifle, scope and accessories that represent one of the 4 years of production at Holland and Holland, or as it was updated and repaired by British Armorers or other installments of service history. If you are slightly less lucky you may have a rifle, scope and accessories that have been used and improved by private owners and tinkerers, Here is how to spot original features, errant ones and simple techniques to step towards your chosen rifle impression - original factory - war years service - post war British service and post war International service - organised by parts group:
Rear micrometer sight. These were originated for the No4 rifle design by Singer Machine Co, hence they are often referred to as a "singer sight". Early No4 rifles were produced with the micrometer sight by the rifle manufacturer (Enfield Lock - "E over D" for the Trials rifles).
The very first Maltbys and BSA's produced their own and used the associated early marks for each (large B for BSA, stylized M for Maltby). Genuine early BSA marked T rear sight (reconditioned / polished scale face):
When the war expedient models were produced (initially with the "L" flip sight, then those selected for conversion to T status had to have the rear sight replaced with a modified micrometer sight (H&H indicated this had been done by stamping the "S" on the front of the right receiver wall - happened to most, but not all!) Where did the replacement Micrometer sights come from? Singer and other producers! In the British war time contract scheme there were 2 phases of demarcation - early / pre-war marks, and later regionalised contractor codes, For Pre mid 1943 rifles you are seeking the early war markings from Singer (SM), after that seek the regional producer code (S69 - for Southern region, 69th contractor). Here are 2 genuine early Singer produced sights - the SM 41 example was more correct to apply to my 1941 MalTby:
Note the all blackened finish - dark and matt - typical of war time efforts at H&H. The item on the left has been rebuilt, but features other components marked "SM" for consistency. The last year observed on these sights using the SM mark is 1943 as per the right hand example, then the S69 code is used - again on major components (sight ladder (top left of the face), cursor (left side), elevation screw (top) and elevations screw nut (back).
BSA experienced a third level of maker coding change - each of its factories were given an "A,B,C" location definition. So BSA Shirley, that produced the No4 rifles was designated "M47C" (Midlands region, sequential supplier no 47, factory C)
The very early contracts at Holland and Holland for T conversion included selected rifles from Savage, Longbranch, Maltby and BSA - this was too much variation for the conversion process to be efficient and by early 1942 only BSA rifles were to be converted. So if you have a genuine Maltby T - it was converted in 1941 and a little into 1942 at H&H while stocks lasted - typically Matlby Ts are nearly always 1941 dated - a 1942 example that is genuine has yet to be documented.
Similarly Savage rifles that are genuine and completed to a fully scoped "T" are rare and early. Some of these rifles seemed to have laid in stores until the end of the war and then them and and the remains of the BSA marks were furiously converted to T status by H&H while the contract lasted. These later T's often went into stock as "Scopless" - a rifle in a transit chest as a spare part - awaiting a need and the addition of a scope and bracket - plus all the other CES. Most of these seem to have been released / imported in the 1980s. So a genuine Savage rear sight converted to T format by H&H is possible on an early 1941 converted and war time used rifle and on a late 1945 scopeless rifles. Savage rear micrometer sights have some unique machining features in the battle peep - which will be missing on the T format versions. Here is a Savage T format sight - with a 'squared S" on all 4 major parts as above: