The plunger type bailers are the older ones that have been overtaken by the silver colouted triangular shaped ones that drop down from the bottom of the boat. The older plunger type ones can come a cropper if you come ashore and forget to bring them back up which does not tend to happen as much with the newer Anderson type bailers as they will in the worst case been pushed back in towards the hull of the boat. There is nothing saying that you cannot replace one type with another type of bailer, but if you want to keep the boat in its traditional fashion the older type may be hard to get hold of. Ask any of the vintage sailers (Tim Gatti is a good start) if they have any leads.
Good luck with the boat.
Good luck with the boat.