First, thank you for the information and link. I have a deep interest in the colonial era. Virginia was struggling with inflation well before that, but their course was no longer available: to be paid in British treasury notes; on 4 Dec. 1762, a Virginia regiment refused to be paid in Virginia notes due to inflation (Journals of the House of Burgess,1761-1765 pp 124/133).
Regarding the use of portions of pounds, this is not too unusual for the period. For example, this is from a Virginia Act (law) from 1730 (italicized to show where it is):
I. BE it enacted, by the Lieutenant-Governor, Council and Burgesses, of this present General Assembly, and it is hereby enacted, by the authority of the same, That the sum of ten pounds and an half pound of tobacco
, be paid by every tithable person, not exempted therefrom by law, within this his majesty's colony and dominion of Virginia, for the defraying and paiment of the public charge of the country; being the public levy, from the first day of February, one thousand seven hundred and twenty seven, to the one and twentieth day of May, one thousand seven hundred and thirty.
I am sure that there are more examples in Hening's Statutes at Large:
Part of it might also be, I don't really know, that British pound sterling was not on a decimal system and guineas sometimes were 1/7 of a British pound sterling; lots of coinage was in circulation and of course in VA tobacco was still being used, was not on a decimal system at the time. Note payments shown in currency and tobacco:
(now if only my Confederate bonds had some value, but I digress...)