Vern,
The Pal nuts I have are 1/2 - 20 thread, 3/4" hex head. They are stamped and plated lock nuts. They are not sized as metric, but they don't seem to know the difference! I used trial and error to order boxes of these and to some up with acceptable substitutes. They fit M12 - 1.5 and M12 -1.25 threads equally well. I found that they work well and are a match for those used on suspension components. They can easily be black oxide coated and oiled.
I did not find a match for the 10mm Palnuts. I have a few originals, but not enough to make up the dozen you require and leave me with spares. Also, I found that there are two different 10mm Palnuts. One is 14mm hex head and the other 17mm hex head.
If you'd like, I can send the 4 12mm palnuts.
Terry