Scout Regt. Scope question

I have recently acquired two Scout Reggie scopes with the swivelling eyepiece plate being completely blank and acting only as perhaps a dust/lens cover . All my other Scout scopes have had the dark sun filter mounted in the plate. One of the two scopes is dated 1940 with the No.112 2 On both scopes the eyepiece housing which carries the swivelling plate has no engraved numbers and also lacks one of the notches into which the plate pin nests. I just wonder if someone with more knowledge than I can throw any light on this. Did the scopes have a dust cover initially and this was later turned into a sun filter-or what. The eyepiece assembly on both scopes appear to be original .

I think you'll find that these are all variations and anything you wanted was available. You'd want the sunshade for use at sea and not so much when stalking...

Thanks for the info. I never gave a thought to variations .I thought they would be all the same. A dust cover makes sense for certain conditions. Cheers, Tony

The S initial after the Mk2 indicated 'shutter' as in 'with a shutter'