If you SPECIALISE, it gets worse (or better, depending on your point of view).
Look at the SMLE MarkIII/III*.
Entered production at Enfield, BSA and LSA in 1907, Ishapore and Lithgow 1912, SSA 1915, NRF 1918.
BUT there are a few NRFs marked 1917: end-of-the-year parts assembled in 1918 after the name change. And there are said to be a few 1918 SSAs assembled likewise from Bodies already marked.
So your SET just from that plant should be:
SSA 1915 Mark III
SSA 1916 Mark III
SSA 1916 Mark III*
SSA 1917 Mark III*
SSA 1918 Mark III*
NRF 1917 Mark III*
NRF 1918 Mark III*: SEVEN rifles with FOUR dates, all from ONE plant.
LITHGOW made rifles every year but never did switch completely to the Mark III*, even though the rifles were marked as such (my 1918 has a Cutoff Slot)...... and they kept on making rifles right up until the change-over to the FAL..... some every year, even though some years are shockingly-scarce.
LONDON SMALL ARMS made rifles up to and including 1918 but only changed-over completely to the Mark III* right at the end. They made nothing after 1918.
ISHAPORE built rifles every year, rebuilt rifles every year, made some India Pattern rifles which were built nowhere else, made some single-shots, Muskets and even the 2A1 in 7.62 NATO. They are making every part today but no longer manufacture Bodies, or so I am informed.
PAKISTAN did not exist and so did not make the rifle at all..... but POF at Wah Cantt makes all the PARTS today.... except Bodies.
And there are Commercials, Test rifles, Trials rifles, special lots for Iraq (1936 and 1938) and Siam (1922), small lots for other Governments from time to time.
Enough variety just in that one rifle to keep a man happy and confused for a lifetime.
And broke.
Can't forget that part!
Hope this helps.
.