Recently purchased a nice Campagnolo Mirage rear mech used for a steel frame build in the traditional style.
Campagnolo is new to me having been more of a Nissan man than an Alfa Romeo afficianado in the past. As my mid life crisis turns into a full time career I have decided to indulge myself.
The lower jockey wheel appears very stiff and in need of tlc. I note the upper jockey wheel is a normal bushing but the bottom one appears to be a 'sealed bearing' type arrangement.
The codes are:
2302012 Upper
2302013 Lower
..thus confirming a difference.
(8 spd I think).
Before realising the difference I confess I tried 'driving' out the inner ring of the bearing, believing it to be a bushing that had merely got clagged up with rust or whatever. I think I can safely say no lasting damage has been done.

Can I do anything to restore or replace this sealed bearing? I have tried lubing it and it is now soaking in some oil as we speak. I am sceptical about the prospects as presumably 'sealed' means 'sealed'.
Obviously I am aware I can buy replacement parts but the price is crazy, more than the mech itself cost.
I have considered 'bodging' it with a shimano wheel or something but this is a bit of a vanity project to be honest and so I am trying to do it to an OCD/perfectionist standard. More time than money or sense. It will be a high days and holidays bike. Any help and guidance gratefully received.