How about asking that on the USCF forum?
Perhaps your not a member of the USCF?
In any event, if your a member, you can ask the USCF directly for historical data. I think it mostly goes back to the early 90's.
Prior to that, the records are on paper, mostly limited to searches of specific records.
Curious if anyone knows if USCF has an API if you wanted to download historical (and current) data systematically.