Top down:
SMLE Mark I or I*
SMLE Mark III
SMLE Mark V
SMLE Mark VI
Buffdog, if you like the sights on the Mark I, drop by for coffee and check out my Navy Mark I***. It still has the original fully-adjustable rear sight with the Indian water-buffalo horn adjustment buttons. Very slick indeed. These sights disappeared in 1907 with the introduction of the Mark III. The Mark I*** was supposed to be an upgrade of Mark I and I* rifles to full Mark III specification, but the Navy must have been Sinatra fans: they "did it MY WAY" and so the results are..... uneven..... at best. Army rifles were held much closer to spec; you can't tell my Army Mark I*** (LSA, 1904) from a Mark III without looking at the butt socket markings.
That is a VERY nice display of rifles. It holds one rifle which is extremely important historically and THREE rather extreme rarities.
Not many racks in that class, anywhere, one would think.