An interesting scope combo.

[Bruce_in_Oz]

Just a wild guess from the Penal Colonies.

I suspect the little folded tabs at he lower rear of the L1A1 dust cover may be a hangover from the construction of the early X-8 series covers that retained the ability to use those various charger clips. With a "full-length" cover, as the rifle recoils, the cover cannot "slide forward"; with a "half-length" cover, the tabs were "needed" to stop such movement.

As the design advanced towards the "definitive L1A1", the recesses in the body, and the dust cover tabs never quite got scrubbed from the drawings, so, here we are today chatting about arcane details on vintage hardware. Chicken / Egg and "Tab / Recess".