What I have done is use plastic weld to stick the broken end on, but it is slightly out of line, presumably some distortion happened when the broken end turned round and hammered the oiler cap off.
I then drilled a 0.5mm hole through the centre of the tapered wedge (Looks like the full size one adjusts the bearings by pulling that wedge up with a bolt) hooked a staple in and scratched a mark on the rod for the hole for the other leg of the staple, drilled this hole then pushed the staple in.
I grooved the plastic slightly to take the staple, with the dremmel, cut the staple legs short, and pushed it in finally and bent the leg over into the groove.
Whilst I had the dremmel out, I tizzled around the staple with a dental burr and inside the voids around the wedge to key the glue, then looked for the metal loaded epoxy, gave up and used a blob of araldite to cover all the staple and hopefully form a strong fillet.
The araldite is a bit too rubbery for my liking, also it never seems to stick to LGB plastic very well.
All in all, it used up over an hour of my holiday, so really I would have been better off paying for a new one.
Martin