Here are the basics of my two Trials 4T's. IIR I'll add additional info when I can sort it out.
1931. A2144. 4 click rear sight. Matching bolt with transverse striker keeper screw. Mag is a replacement but all other parts are original AFAIK.
Scope serial on butt is indistinct but I think probably reads 4621. Rifle came to me sans scope & bracket, though with pads intact.
1933. A0075. 6 click rear sight. Some replacement parts including bolt, though all appears to have been done long ago & probably whilst still in service.
Butt original & rifle looks to have been fitted with scope no 3167. As with other rifle this one came sans scope & bracket. Body pads are original.
ATB.
P.S. Both have correct waisted foresight protectors & cut-offs. (Your post reminded me, thanks Blurred Edge!).