The numbers FN450/649 (200), JW550/669 (120) were allotted for FAA Seamew I. Only FN453, 463/467, 472/475. 483. 489, 573, 608, 622, 631 were delivered for a total of 16.
JK663/669, JZ771/774, KE286/304 Queen Seamew I (Target Drones) were allotted with KE286/304 never delivered>
The U S Navy Bu Numbers for the Curtiss SO3C-2C (designation for Lend Lease to Britiain) were 4784/4792 (9), 22007/22256 (250). None of 22057/22256 were delivered to Britain and only some of the others were delivered.
From the above info it looks like only 16 Seamew I and 11 Queen Seamew I were delivered to FAA.
Sources:
http://home.att.net/~jbaugher/navyserial.html
British Military Aircraft Serials 1912-1966, Bruce Robertson, Ian Allan Ltd
US Military Aircraft Designations and Serials 1909 to 1979, John M Andrade, Midland Counties Publications
Curtiss Aircraft 1907-1947, Peter M Bowers, Naval Institute Press
British Naval Aircreft since 1912, Owen Thetford, Naval Institute Press
I hope this helps.
bill word