Bottom trunnion

Hi All. Steve has asked if I could send out this request .if you have such an item the contact him :

I have a thought for modifying the bottom trunnion to polyurethane bushes and am therefore seeking any defunct units that anyone may have retained.
However as the change will include increasing the hole sizes where the original threaded bushes are fitted will render them unsuitable for subsequent exchange.
So effectively only scrap units would be appropriate.