And as recent Forum posts have shown, there are scammers out there waiting for the unwary. An old machine will lack the features "normal" to more modern machines, may be worn or damaged, and could have parts missing. Finding replacements can be problematical, even IF a part can be found. It may be even more worn or damaged than the part that you want to replace. Or your machine may be a Mk1, and the part, when it arrives turns out to be for a Mk2A. and so either will not fit (They upgraded / changed the gears, sizes or threads? May even have inverted things like dovetails)