As Maxwell Smart says...there may be minor cosmetic differences, but for the MkI* on...they'll be substantially the same as the ones on the MkIII. What are the differences on the ones you have? Pictures?
And just because someone's bound to say it before long...there's technically no such thing as a "No1 Mk1". At the nomenclature change in '26, ShtLE MkIs and the various Converted short rifles were specifically exempted from the nomenclature change. A bigger deal to some then to others, but there it is.
"If ye love wealth better than liberty, the tranquility of servitude better than the animating contest of freedom, go home from us in peace. We ask not your counsels or your arms. Crouch down and lick the hands which feed you. May your chains set lightly upon you, and may posterity forget that you were our countrymen." --- Samuel Adams