Hello Arnaud,
I don't know even if Parnall's Hurricane was salvaged or remains buried into the ground but yes, it needs an investigation there... Why are you pretty sure that his aircraft was never dug up? Have you any doc confirming that?
Arnaud, you speak about L1639 OR L1941 (P/O Sibley's L1941, still MIA, but this is another story...

)???
As written in N.Franks FC Losses, he is buried in Chaussée-Notre-Dame-Louvignies, in Belgium.
F/O M.E.A. Royce bailed out and his aircraft crashed in LOUVIGNIES. Same combat so I presume same crashlocation area?
I presume this was not Parnall's aircraft recovered in France. Moreover Dave speaks about a 85 Sqn pilot who bailed out. So I think this a case of 'melting-pot' (mixing info's)!
Any sweep here ?
ClinA-78