Looks great Rick!
Requires precision with the jig construction but once perfected, ready for use whenever needed.
Is your router bit a straight flute or spiral?
Thinking I could just cut the "U" relief for the bit with a core box bit of the same diameter. Easier for me to sneak up to the correct depth by raising the core box bit in the router table vs moving the fence.
Maybe that is how you cut your groove?