Hi Graeme,
I don't think its the bush or the oilite type bush in the vertical stab that we need.
The bush is sandwiched between the skin (top hinge) & bracket with a clinch nut.
For what ever reason it seems the bush has worn through & broken the top hinge on ours & worn a pocket in others (as per the painted white example).

Thanks for the continued support.
Hopping Elliots had not suffered the same fait as ours!