I am helping a mate working on a bike (old Honda not sure which model). So far, we’ve got a few minor problems: (1) The stanchion tubes have a few small corrosion marks. We know that a good option is to get them professionally re-chromed, but then that would take the fun out of our DYI project! So we are thinking of using some kind of fine metal filler to fill the dents, then smoothen it out with sandpaper. Is there something on the market that we can use for this purpose? i.e., something that can resist oil and pressure from the fork seals, and will stick permanently? (2) The main carb seal is shot and we can’t find anything that fits. Of course we don’t want to seal it permanently since we still need to open the carb for cleaning etc. Is there some kind of sealant that can be used to make a non-sticking seal? Or anything else that can be useful for this? (3) The bike has a metal air box which uses paper filter. The paper is gone and we are planning to replace it with foam filter. Is that ok or should we stick to paper? Any comments?