Shortly after I got my 1st T from Epps,traded 5 Enfields for it.The smith that was working there at the time called me about a sporter with a cut barrel came in.found a scope for around 500 sent it to Peter Laidler for service and built my 2nd T.My 3rd was a lamp that came out of a school or museum. Barrel was still shootable.I wish I still had half the stuff I have traded away or sold in the past.
Wishing on the things we once were privileged or forced to experience isn't worth the time or angst.
Just be happy you had the opportunity to enjoy and take care of them for awhile.
I remember going into an Eaton's store in Vancouver where there were a few dozen No4 MkI T rifles in their chests, with scopes in cans at the horrendous price of $125 each, take your pick, pay the cashier, and carry it out the door. The rifles looked like they were new out of the factory.
The price seemed incredible to me at the time. I was ten years old and my father didn't clear that much in wages over two weeks.
I knew what I was looking at, but never thought I would ever be able to afford one.
Since that time, I've had the privilege to be the custodian of several, in various conditions.
The worst came out of India, where it had been purchased as surplus from the UK, with a MkI scope, issued to their Army, then passed onto their Police.
It was well used but well maintained and a few things had been "altered" to keep it serviceable. Of all the No4 T rifles I owned, that one shot surplus ammo very well, usually into two moa or less out to 300 yds.
The No4 T rifles are acceptably accurate for their intended use but they most certainly aren't tack drivers with most of the issue ammo available. Like many of the sniper rifles of the period, they did the job and IMHO was one of the best purpose-built sniper rifles of the period.
I don't believe they were any more or less accurate than any of their counterparts, and the few times I've had the opportunity to shoot them against each other, under the same conditions, with ammunition loaded to each of their preferences, they were all very similar accuracy-wise.
OP, good luck with that build, it should be fun and a great learning experience.
The source for fore-ends given to you by tiriaq has some original pieces available in EXC condition. These would be suitable for your build.