True enough in both respects.
Having a date is great. As I'm, to put it mildly, a bit over prone to deducing aircraft type from serial numbers I guess I can't be too critical. If the seller looked up 2936, as I suspect at :
http://airhistory.org.uk/rfc/aircraft.html
Then indeed we're looking at an Avro 504A.At least he tried.Or, it could be that given the service history of 2936 at that site is incomplete, that we're looking at an 'Improved Type 504A, rather in the manner that there was a Short Type 184 and the Short Impoved Type 184.
Regards,
Clint