BCBrian
I have two-fingered out the system I use several times here and you should be able to find it fairly easily... I have tested every finish I know of and measured their performances against standards and there are only two finishes that meet your needs, IMO.
Any good very slow-setting epoxy (G-1 and G-2 from Industrial Formulators out of Canada are my favorites) will make a waterproof seal coat like almost nothing else will. An oil finish of your choice atop the epoxy will look like a straight oil finish, repair like a straight oil finish and go on easier than any oil finish being applied to bare wood.
The other option is superglue... I have never used it as a stock finish, though I know several good stockmakers that have. I have tested it personally on test cubes of walnut against my epoxy finishes and it is as good in the waterproof department.
The only negatives I have relative to the superglue is the fact it shrinks the wood, so a tiny amount of pride has to be left in your inletting. I wish I could give you a number to work with there... but I cannot.
I intend to use it soon on a stock so I can comment from a personal perspective.
If you cannot find the threads or have other questions I am very easy to reach and will happily do whatever I can to help.
best to you
art
