US Dollars were not the established principle currency until 1792. Before and for decades after people would use standard or localized British units (so a Pennsylvania pound was different from a Massachusetts pound, each different from the British pound sterling) equivalent to whatever they had on hand (like Spanish bullion for example).

Like even in the 1820s, John Quincy Adams reported that the dime was “utterly unknown,” whereas a Spanish reale would be accepted as a shilling in New York, nine pence in Boston and eleven pennies in Philadelphia, all based on the “absurd” application of English denominations to Spanish coins.

Tbh I'm not quite sure what coinage or paper money Knox was actually being paid in. Certainly not continental dollars as that money collapsed and was replaced with usd at at a 1000:1 conversion in 1792.

New York was using a localized Pound that had mixed sterling and devalued paper money but he probably was not using that localized rate when writing down expenses (everything would be worth 1/3 as much which doesn't quite make sense to me).

He would have been used to using pounds, shillings etc and that's probably why he wrote the list like that but whether the physical money he was paid in and used was pound sterlings or local NY pounds or some other coin like Spanish reales, not sure.