Thanks Luis.
I didn't really explain properly.
What I will most likely do, is to to replace the plastic retraction jack (already thinned-down to a more scale appearance) with a length of alloy tube, and fit another, short length of tube in place of the original, plastic mounting point, on the top of the nose gear main leg, or, more likely, insert this into the top of the leg, to attach inside the wheel bay, and add strength to the leg
The jack will locate into an angled plastic, or perhaps brass tube, glued to the 'roof' at the rear of the wheel well, to add strength to the nose gear, as there will be quite a lot of lead weight directly above it, needed to keep the nose wheel down and prevent a 'tail sitter'.
A block of plastic, or something similar, will need to be fitted directly above the mounting point on the main leg, into which the new mounting point will be attached, as it's impossible to access the original moulding to drill-out the remains of the plastic pin.
The retraction jack won't be totally accurate, as the front section of the real jack was a forged, or cast, shallow 'H' section, attached and hinged to the tubular rear section, but this will be impossible to replicate in this scale, without access to miniature engineering machinery.
But as it is under the aircraft, and partly hidden inside the wheel bay, it should look acceptable enough I think.
Hopefully, this will all make sense when I eventually post pictures of the repair / modification.