Hi twoess, it all depends on how bad the wear is and if it is affecting the movement. With great wheels (the wheel the mainspring is attached to) yes I would bush it if it was worn, the usual rule of 5 degrees slant does not apply to barrels as this is a heck of a lot of play for a large pivot. If the hole looks remotely oval or I can see movement in the hole when the wheel is moved side to side I would bush it. With any of the levers I have yet to come across anything that is so bad it has needed bushing but again if the hole looks oval it would not do any harm to bush it, the only time you need to be careful is if the hole is very close to the edge of the plate and there wouldnt be much material left once you hade cut the hole large enough to fit the bush.
Hope that helps 
Paul.
