Speedmaster 2915, Length of the unpainted "second hand"?

Hi,
I have been trying to find out the correct length of the original Speedmaster 2915 "silver/unpainted second hand", there are plenty of discussions regarding the broad arrow hands, lume, length and shape of lume but I am struggling to find anything on the "second hand".
Do any of you know the answer to the question?
I am not "fishing" when I say this just trying to get an answer to a question I have been asked.
I have an Omega "second hand" it is unpainted, it is in its original packet marked 280W29, it is 14.5mm from the centre to the end of the hand, the overall length is just shy of 19mm.
I always thought it was for a Railmaster but the person has said he thinks its for a 2915, can I confirm......
I know at least one of you will know, any help would be greatly appreciated.
I have attached a couple of pictures.

Thank You Mac,
I can now report back.
Much appreciated.

I think i have a 2915 second hand, need one?