Are players with English ratings considered unrated in their first US Chess tournament? My flyers say that unrated players are ineligible for class prizes, but the translated ECF rating would make them eligible for the lowest class I have.
I think the language used in 28D answers your question…
28D: Players without official USCF ratings are eligible only for place (or top non-class) prizes and prizes for unrated players unless alternate procedures are used to assign ratings (28E), such as the following recommendations…
The rule book then goes on to show various countries conversions, England included.
If you decide to use a converted British rating for this player, I’d strongly recommend also entering this converted rating into your pairing software, just as though it were an actual US Chess rating, so that it will appear on the pairing sheets and wall charts you post during the event, and so that it will be used by the software to make pairings.
Don’t forget to check for a FIDE rating as well. I hear that a number of British tournaments are rated in both systems (though maybe not a section for players in that rating region).