Hello, and thanks for the answers!
my intention is building a 1/72 Sword F.1A with some Airfix parts. The two are identical in shape/size of the fuselage (Sword obviously simply "filled the gap" left by Airfix not producing F.1 and F.3 variants and reproduced the same general shape). When I compare the fuselage with the SAM modellers datafile plans the length is more or less correct while the fuselage is not tall enough, in particular in the nose section. It seems to me that Airfix is more accurate than the plans, and here comes my doubt about them.
@gingerbob : thank you for the link!
@Giorgio N@tempestfan : if you have available a copy of the Echelon or DaCo plans I'd be very happy to try them!