A lot of Scottish breweries such as Deuchars still used direct fired coppers that gave a lot of caramelisation as the wort contacted the hot metal.
Not all Scottish Ales are caramelised. I grew up on them and they ran pretty much as follows in the pubs and many of the old ones still in production.
"Light" - equivalent of English mild ales. Dark and about 3.6% ABV. South of the Border it is just called "Scotch". Pint of scotch please. Makes southerners tremble in their boots when they hear that.
"Heavy" - equivalent of English best bitter. Generally amber in colour (Tennents, Maclays, although some were dark). However it wasn't really all that heavy, around 4.2% ABV. Canned version, McEwan's Scotch is still a good mid colour example. Wm Youngers Tartan was a popular tap version same colour as English best bitters, don't think it's still made.
"80/-" - various names - has had a revival with new breweries, and is the strongest. Generally dark. OP's version would be a good example of 80/-
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