Because you're all so good at this. 
This text from c1750 is about money owed, and I reckon one of the troublesome words is "prin(c)" for principal.
But what on earth are the others?
My attempt at transcription:
... Fifty Seven pound Nyneteen Shilling Scots of prin(c)[?] Five pound fourteen Shilling Scots as expense[?] of plea and thirty Seven pound Sixteen Shilling as the ?? of the said prin(c)[?] Sume resting at the Defuncts death In a bill...