re: pallet wood good or bad?

Here is a board with a sanding belt stretched over it but sandpaper glued to a board will also work .
This could be used for your joint gaps by making two halves and then jointing them on this but the board has many other uses around my shop like leveling a box bottom or sanding small parts ETC.
I clamp my board on the extension table of my TS which has a vise .
The other thing you can do is clamp the pieces to a board and use a dowel saw and recut the joint kind of what Madts suggested .