I have an acquaintance who has done as you plan, also he has owned absolutely original and very nice shape No.4 "T" with very solid provenance - complete with most accessories, including the "matching" number transit case. He has spent years to learn what "real" looks like, how it was done, where to find the "real" stuff.
From him, I understand the "pads" (scope mount bases), get installed to match up with the specific side mount (bracket?), so not a random one size fits all - need to have the two pads and bracket in hand to fit them. The pads are located, drilled, tapped and soldered into place. Then pads machined, etc. to be "collimated" - centre line of rings is also centre line of bore - then install a correct scope. "Real" originals have various serial numbers and other marks, marked on scope, ring mounts, butt stock, etc. to show that they were built for and with each other.
From him, is very difficult, to impossible, to find authentic pads and mount (bracket) assembly, and correct screws for all. There is a particular Canadian guy who is the "go to" guy for servicing the original "T" scopes - seals, oils, grease have dried up and seize adjustments, lenses separate, and so on. By itself, restoring the scope is a significant project. A good number of "real" original British No. 4 "T" were converted to L42 rifles by British military.
Would have thought that once Holland and Holland was done with them, that they would be awesome shooters. Maybe for that time, but not so much today. From Wikipedia: "These rifles were designated as the No. 4 Mk. I (T). The accuracy requirement was ability to place 7 of 7 shots in a 5 inches (12.7 cm) circle at 200 yards (183 m) and 6 of 7 shots in a 10 inches (25.4 cm) circle at 400 yards (366 m)." So, 2 1/2 MOA at 200 yards for 7 out of 7 shots, and similar 2 1/2 MOA for 6 out of 7 shots at 400 yards. Haha! - may not have been really adequate for deer hunting, as per some current Internet posters...
One does see curious stuff posted for sale - pads clearly not lined up, (or incorrectly placed), some sort of poor quality reproduction mount, a Bushnell or Weaver sporting scope installed, incorrect and/or not matching wood for the receiver that was used, and so on. Depending on the serial numbered, authentic matching accessories that come along, I think, these days, that the "real" originals sell in range of $10k to $15k in Canada - maybe higher (or lower) than that elsewhere in the world. Something that someone "put together" with more or less knowledge and more or less skill might sell $1k, and up - depending on what a buyer knows or is prepared to pay. Some receivers (body) would require extra machining steps, so, for example, none were ever built in Britain on Maltby made receivers.
So, for a straight, undamaged receiver body (not bent or twisted), the original pads, and the original screws, but nothing else (no mount, no scope, no bolt), I suspect few people would pay more than about $150 to $200, but a pure WAG - I have never bought or sold one.
It might sound odd, but "matching numbers" for receiver and bolt really does not amount to much, if any value - those rifles all pushing 75 years or more since built - even "all matching" would need the checks to verify that lugs are still bearing evenly, that the receiver seats are not worn out, that headspace is still within spec, and so on. For example, does the particular bolt head installed on that bolt body still "clock" within spec? Is the little "nub" on the receiver body for anchoring the magazine still present and within spec? As I understand, the "T" was built to use a specific standard of ammunition as was used by military in WWII and some years later, which may or may not be able to be found any more - certainly were not built around commercial soft point Winchester or Federal offerings...