I ended up with a very large spline after playing with the jig. No worries, this is my pallet wood pile to practice with. As far as I can tell, this is a pine box with cedar splines, top, and bottom.
My first attempt at routing an edge, lot’s of burs on the end grains. What causes that?
The box came out nice. I made 45 cuts and glued together with out clamps. I used tape and checked my square before leaving it to dry. It seems to sit flat on the ts.
I worked off the spurs with a wood chisel and sanded with 240.
-- I'll get it done when I get a-round-tuit.