Gord is another canadian who managed to escape under/through the razor-wire some years ago...He recently scooped a very clean MkII** Military up from one of the auction sites....
Here's the scoop (IMHO; anyway) on the receiver bridges.
1. Commercial MkII**'s- I currently have seventeen of these in my collection, and ALL were originally factory-fitted with bridges, but not necessarily sights.
Broadly based on serial ranges, the earliest ones were fitted with short, milled bases. Next came another slightly longer milled base. Towards the end of production, the barrel sight was eliminated completely, and the military milled base with lips for the stripper-clip machined in was fitted.These were normally fitted with a Commercial CanTool MkIII Battlesight with a very small aperature, and no inspectors mark on either the base or the sight itself. Many different 'approved' bridge sights were commercially available to shooters- I have three variations of BSA sights, one side-mounted Parker on a BSA base, a gem of a sight by Westley-Richards, three different CanTool commercial peeps, of course VSM-Peddie, others...
Military MkII**- the first three variations came with a receiver base stamped from sheet steel, with flimsy lips for the stripper-clips.The final version eliminated the barrel base/Sutherland sight and fitted one-piece top wood, and used the milled base fitted with an inspected, small-aperature CanTool MkIII battlesight.As well, all four screws securing the base to the receiver were center-popped (staked) at each end of the screw-slots.Some, but not all, bases were also whacked with an Inspector's stamp. I have four variations of the Military MkII**, but have owned and handled many more, both Military and Commercial. NEVER have I seen or heard of a MkII** that still has an undrilled receiver, so until someone actually comes up with one that wasn't built up on a 1905-E receiver, I stick with my supposition that all versions left the factory with a receiver base.
The serial range on Gord's falls in the middle of the change from the stamped-from-sheet base to the improved milled base. (hole centers are the same) so either will fit his rifle.
Any MkII** either Mil or Comm without drilled holes: please surface immediately!