Just a quick update on the new plug. I use a dry wall jointing compound for the filler. It's relatively cheap, sands very easy and the finish is more than adequate once sealed with water based varnish prior to releasing wax. Here I'm in the process of applying the third and probably the last layer of filler.
I'm still undecided on the name for this IOM. It's currently a choice between Cult and Shwmae