Different 44' Longbranch

[ssj]

I have seen a Lane sight plate attached using a hole in a very simmilar spot.Central made sight plate to suit the No.4 mk1/2 but I think Lane,Austral,Rawson were only made for No.1mk III and adapted to fit.(some one will prove me wrong ) I will try to dig up a pic. of the Lane on a No.4.

Ive seen a few No4s in NZ with that threaded hole, I suspect the local owners to tight to buy a no4 central bracket just used their no2 mk3 bracket.