Splitter teeth/stabilizer needed, wood slipping when splitting

If you have a stick welder just run a bead in an X pattern
corner to corner That's what I did with mine and it works good

The previous owner of my splitter welded crosshairs on a bullseye and it works great.

Yup, just get someone to weld an x. Do an internet search for other splitter images if you need some ideas. If the weld isn't sharp enough, you could grind the edges down a bit to make a stronger edge to hold the wood.

I welded a cpl 5/8 3/4" ish nuts on mine.

Key stock or square nuts or whatever is handy

I've seen people drill and tap and thread a setscrew in from the side opposite the wedge and let it protrude about a half an inch or so out on the wedge side of the plate and then sharpen those to a point. Seems like it would work well but seems like a lot of work

Pieces of flat bar with gaps between work well
Make the flat bars thick enough so the tip of the wedge goes past the flat bars. This eliminates the gap at the end. It works much better on stringy wood where the last gap is not cut by the wedge

Cross-section short pieces of angle iron about a half inch long provide a V shape and seem to work OK

Short pieces of square tubing or pipe do NOT work well. They bite well but the closed cross-section fills up with wood bits jammed in there