"Agreed, could you, or anyone, provide a recipe for this simple lime mortar?"

I'll go to Vitruvius again,

"mix your mortar, if using pit sand, in the proportions of three parts of sand to one of lime; if using river sand or sea sand mix two parts of sand with one of lime....Further, in using river or sea sand, the addition of a third part composed of burnt brick, pounded up and sifted, will make your mortar of a better composition to use"

supposedly the crushed bricks produced good frost resistance. the hydraulic and semi-hydraulic stuff is a little over my head.

some recorded proportions from up near your parts Mark,

One part lime to 2.2 parts sand : Quebec
One part lime to 2 parts sand: Nova Scotia