OP - "put it back to what it should be" - there were two versions - Mark I and Mark I* - and at least three distinct stages that all are "as it should be" at different times and then each of the three makers - so at least 18 variations of P14, plus those made up as sniper rifles. A couple of us have been trying to figure out each characteristic.
From the factories in USA, the Eddystone often had the "fat boy" stock, Winchester and Remington never used that - so three different styles of stocks, at least, from the factories - all were equipped with the volley sights, as were Britains SMLE's. The one marked front volley sight base that I have is marked "W" on the back - so Winchester production. Should be "R" marked and "E" marked as well.
Corrected as per Charles Stratton book - pages 24, 25 - By Spring 1939, Britain had a program to overhaul their P14's that had been in storage since 1919 - was called Weedon Repair Standard - work was done at a number of British armouries and gun making firms - Stratton lists 10 of them and the identifier codes used - front volley sight arm removed, the spud that it rotated on was ground flat to the base - the base was left in place; rear volley sight arm cut or ground off the P14 base for the bolt stop spring, stocks repaired - in some cases, P14's apparently fitted into M1917 stocks which never had volley sights at all. As per Stratton, about 55% of total P14 production was converted - roughly 677,324 rifles that Britain had. Later, during WWII, Britain had British contractors supplying stocks and other parts - those WWII British made stocks never had any provision for volley sights at all.
So three stages - from the factory, after Weedon Repair Standard and after WWII. All are authentic and "original" - all done by British Army. Only first instance, as they left the three factories, did they have volley sights on them. So far as I know, if front one disabled, then rear one also ground off. Never had one without the other.
We found some pictures of what we think are original WWI British sniper rifles. By far, most of them were never equipped with a scope. They did, however, install a "Fine Adjustable" rear sight - more precise to adjust than the standard rear sight. WWI British sniper was an above average shooter, using an above average rifle (for accuracy) and could make use of the fine adjustments to take "pot shots" at the other guys, often from a vantage point behind their own trenches - once their location identified by the other guys, was typically target by artillery - so a couple shots, then MOVE... Late in WWI - like last several months, some 2,000 P14 sniper rifle were equipped with scopes. Apparently, only the "W" made P14's were ever used as sniper rifles. From pictures, it appears the volley sights were removed when the Fine Sight was installed, but not sure that the pictures that we saw are of authentic or not.
Time is getting away on me - more than a year ago I contacted DS-Solutions in Great Britain - he had three original front volley sight units, and had sent them to a "jobber" to have reproductions made - so the front volley sight arm, the wavy washer that was used and the attaching screw. Those three parts attached to the base and its cross screw within the front stock. I never did follow up to get any. That "W" marked base I have, still has the "spigot" - was not ground off - so a front volley sight could be re-installed. I have another one that has had the spigot ground off flat - so apparently like was done in the Weedon Standard Repair. I have seen "re-built" P14's offered for sale that have had a SMLE front volley sight installed - it is significantly shorter than what the P14's were equipped with.
So as mentioned above - at least two versions of Eddystone stocks were produced, plus the "W" and the "R" - books here by Stratton, Ferris, Skinnerton attempt to identify some of the subtle (and not so subtle) differences between them - best ID of course is the rondel stamped on the right side butt - another Weedon Standard Repair was to remove that round brass disc and insert a wooden plate - often the ID rondel got sanded off at the same time - I have several "sporter" P14 stocks here - hard to tell which might have been Weedon work, or somebody else making a hunting rifle.
So kind of have to "pick" the era, then "pick" the maker and assemble the parts. I have not had much luck in finding original P14 stock and hand guards. Everything kind of hinges on that. Only the first "era" - as from the factory - would have had the volley sights, and the rifles would have been all matching - 4 serial numbers on metal - I have one "E" stock with the serial number in the barrel channel, but other stocks here without. Also, "all matching" likely includes the little maker's mark found on virtually every piece, except coil springs and screws - so likely 40 plus pieces of an "E", "R" or "W" M1917 have, or should have, a little "E", "R" or "W" stamped on them. Then have to read up on the metal finishes - each of those stages may have altered the metal finish, so an original WWI floor plate latch might look different than the same piece after the WWII re-build. All fun!!