upvc hinges

This is a "did you succeed" rather than a "how to" question. I have 25 year old uPVC windows with Roto (?) tilt swivel hinges /gearing etc. The mechanism is unobtainable and one supplier has suggested a complete replacement system . Even with labour, this would be much cheaper than a complete...

After many years, my door has started to rub at the bottom corner (far side from hinge). I seem unable to adjust anything and I can't find any image of the hinge. At the top and bottom of the hinge, there is nothing to adjust - when the plastic caps are removed there is only a smooth round pin...

I am in a bit of a state as were to go setting the door back up The door has a slightly wider gap at the hinge side from halfway down the door Do i have to remove the cover as shown from the inside to get at a adjuster or is it all done by the allen screws that i believe are under the caps ...