On the latest USCF tournament, have you had any FIDE member playing? If yes, how much you increased their rating to match the USCF rating?
The usual rule of thumb is to add 50 points to someone’s FIDE rating to get a USCF rating. That works reasonably well for players rated above 2200 FIDE.
However there are two separate issues here.
If a FIDE-rated player shows up at a tournament, what’s a reasonable rating to use for prize eligibility purposes? Is that necessarily the same as a reasonable starting rating for that person?