Hi Tal,
As requested by are mutual freind for you have a email of my thoughts coming your way.
But heres my opinion on you kuk.
Okydoke, Well first off, This is my conjecture & deduction , as no true contempary evidence is so far available.
So others may disagree, with my conclusians.
I would say the M43 is a sub catogary of mk11s. Almost a high quality M.43 with particular features.
With your kuk I would surmise that as the bolster is brazed that pretty much, takes it out of the M.43 catogary, which, I see as always having integral or solid welded bolsters. {Not brazed.}
The Other feature some regard as m.43 are the lack of a projecting finger ring on the handle, Although persnoaly I have seen many 1941 & 42 kukris without the ring that are still clearly marked as the mark11.
I have also seen a photo of a ww1 kukri without them, {the projecting ring}& a different ww1 kukri is in my possesian that a solid welded bolster.
The stamp I would read as JNB43 not JN B43
I belive J.N.B. is an Indian military manufacter & 43 is the year of production.
They certainly were making kukri from 1941 to 1944.{Samples collected or handled by other kukri collectors.}
If you search for a post by Alfred Tan , He got a JNB kukri from Atlanta cutlery. That was discussed at the time.
Overall I would say its a risky speculation to identify a kukri as an M.43 unlsee it was clearly hot stamped M.43 when it was made, as , all the recognising features can be found on mk.2s of earlier dates.{Although I sure some were unstamped, in fact}
The Indian Army also used this method of construction & a similar design on later kukris, slighty smaller in grip size & overal weight.{freuqantly with horn grips.}
Personaly untill proof was found I would class them as Indian officers m.43 varients, rather than true m.43s.{They are ooften stamped. Made in India tempered steel.}
The SA50 mark is the individual British Indian Army munitions inspectors stamp, of the inspector who passed it as of standard. It is often found on both blade & handle.
I guess one could differentiate, a mk2 kukri with "smooth grip" as a mk2 with a "later" "m43 style grip" or a "transitional" model, but that seems to be an imprescise play on words.
Perhaps Mk.2 with precurser features of the M.43 would be most accurate.
{or Just MK.2 for simplicity.}
Spiral