As Embury says, there's some sense in using a Scotch-based liqueur, and although this version of the Bobby Burns is rarely seen, it's worthy of a trial
I didn't know there were at least three variations of this cocktail, and one with Drambuie. I haven't found enjoyable enough cocktails with Drambuie, although I've used half a bottle trying, but this one was very good for me. I used .75 Talisker 10, .75 Monkey Shoulder, 2/3 Carpano Sweet Vermouth, .25 Drambuie, & 2 dashes Peychaud's bitters with a lemon twist & a Luxardo cherry.