I have a similar issue with the wood block at the base of my mast now well rotted. However mine is a Mk1 grp with the early gold anodised mast – this has no interlocking mast foot and step, instead the mast foot is a flat base that simply rests on this piece of wood.I feel this design is fundamentally flawed as any epoxy/varnish on the block simply wears away and quickly exposes the wood to the elements. Since the wood is now rotten the mast rests only on the pivot pin and is making some awful clonking noises when tacking ( or at least I hope thats all it is !) so even replacing with a Delrin block would probably soon see that worn.
I therefore plan on taking out the old mast foot and shortening the mast from the bottom by an approporiate amount in order to fit one of the new Selden composite mast feet and matching step. This will remove the need for a wooden block and get a really positive connection between the mast and the center of the boat.
The problem I can forsee is that it will be difficult if not impossible to get to the two bolts in the step that are designed to prevent forward/aft movement of the foot of the mast. My instinct says that these are not necessary on the Wayfarer as no such system was there originally and to include them would make lowering and raising the mast considerably more difficult and impossible while underway ( for shooting bridges etc .)
Has anyone else done this and are there any issues or thoughts on the following points or anything else I havent considered :
Are the fore/aft foot bolts required?
Should the step be mounted directly to the hull or is a spacer preferred for any reason ?
WIll the prevention of abeam movement at the foot create excess stresses anywhere else?