I can't comment on the fuel water separator, but with regards to the cowling... is it just the cowling or is the lower half of the motor faded as well? If just the cowling, you can relatively easily and quickly pull the cowling, sand it down, prime and repaint it. There are websites where you can also get the stickers or emblems for them as well. The paint, as least when I did the Honda 130 on my old Arima, was readily available nearby and for not too much money. I think it probably took a couple of hours to sand and get the first coat of primer on. Then obviously it's a bit of a waiting game until it dries. But all in all, a very doable project. You could also look online and see if you can find a replacement cowling, depending on the year, make and model... it might be an easy find, and some of them are only around $500 or so. If you'd rather buy new or a good used replacement that is. Third option would be taking your cowlings to a local paint shop and having them do it for you, though again they were pretty easy to do when I did the one on my previous boat.