I mounted one of these speedos on my WM20- 41'.
It works great, but the reading is quite accurate as Km/h,
Although it stated "Miles" on the face of it.
I do have a good original NOS Smiths, but I prefer to keep it safe, at home...
When I tried to install the repro with the original bracket, I could not,
Because (Please note at photos hare)the cable port is eccentric on the Smiths,
Whilst on the Indian repro it is centered, so on the older M20
It clashed with the bracket.
Secondly, the mounting screws on the Smiths are placed vertically,
And on the Indian - horizontally,
So it would probably not be suitable as a direct replacement, but with few
Adjustments, It would probably work.
On the Smiths speedo looking at the face as if using it the mounting studs are at 12 o clock and 6 o clock. On the Indian made ones the studs are at 9 o clock and 3 o clock