Hello,
Currently on delcampe is a photo of a Spad S.904 at:
https://www.delcampe.net/de/sammlero...946678175.html
Is this the Spad 5?
Probably not such a mystery to someone who knows there way around Spad aircraft, but new to me.
Edit. Bet it turns out to be post war and not a mystery.
Regards,
Clint