Well, that is exactly also my question! When reading parts on the book on his Whirlwind experiences I already noted some peculiar things: Whirlwind never flew with additional external fuel tank under the fuselage as stated by this person!
And............that photo of the author in front of his plane is clearly a case of 'early photoshopping'! Whirlwind was at that time still secret, so taking photographs was definitely not allowed then! In fact plane belonged to 263 squadron commander H. Coghlan///////