I received my 'Grumpy' Spitfire today and it's a beautiful rendition of this iconic warbird

(Kiwi no longer my favourite).
However, the prop was 'drooping' considerably and not flush with the fuselage (reminding me of the detached prop issue I've had in the past with another Spit.). Luckily, the spinner was not tightly secured to the prop itself and after (easily) removing it I noticed what appears to be a metal pin and rubber grommet which seem to attach the prop to the fuselage

. The metal pin does not push into the fuselage but does pull slightly outwards, which seems to secure the prop assembly flush with the fuselage (it still seems to work itself loose rather easily). (I'll possibly use modelers putty to secure the pin and grommet before replacing the spinner.)
Does anyone have design details and/or experience on exactly how the prop is supposed to connect to the fuselage?