If you can tell much about a man's character by the company he keeps, the same surely applies to beer. And just look in whose company Blair's Scotch Ale was:
Exeter and Plymouth Gazette, Friday 08 July 1864, page 8.
Allsopp, Bass and Guinness. In the 1860's, they were brewing royalty. Making the most famous and widely sold beers of the day. That Blair should be listed in an advertisement with them is very significant. If only because Blair wasn't even a first division Alloa brewer.
Also significant is the price. Blair's Scotch Ale is the most expensive and by a considerable distance. About a third more than Bass or Allsopp Pale Ale and Guinness Extra Stout. All of those three were expensive beers, considerably pricier than similar beers from lesser breweries. Guinness Extra Stout was about 7.5% ABV at the time and the prices imply Blair's Scotch Ale was considerably stronger. Probably at least 10% ABV.
For a relatively small brewery, Blair's beers were widely distributed. Exeter is about as far as you can get from Alloa and remain on the British mainland.