Re: Where to buy plastic bushing for pedestal seat?
...Depends on the type of bushing you are looking for...and the size.
Regardless, log onto the website of McMaster Carr...this is a general supply company and they can supply you with everything from a hydraulic fitting to a bicycle. I use them all the time for industrial parts.
Type in 'bushing' in the search...from there you can narrow down all the sizes and types and materials....and then order it on line. They are fast too, you will probably have it delivered within 24 hrs. It will work better for you if you can order it from and have it delivered to your place of work. This is not too big a deal with most companies so long as it doesn't cost them any time or money.
Note: if it was a (softer) plastic bushing (Polyurethane, etc?) originally I would attempt to replace it with a more durable material 2nd time around. Perhaps Nylatron or even move up to a bronze bushing (Oilite or equivalent). They are a couple more bucks but they will last longer.