Aha! I think you're right Bakersdozen. I should have looked closer, although I didn't know such a thing existed!
I may look into those one day. Thanks!
Schaller use these with their Hannes series bridges. They are good but you need to rout really accurately for them, or be very handy with fine chisels.
FrankenLab Hand crafting guitars, because Death Rays are expensive.