Hi Don - How about making a pattern of the cut, double stick tape it to the work piece then route your work with a pattern bit in the router following the pattern.  The bearing on the pattern bit would ride the pattern you made.  Then you could use that same pattern to repeat the process on another work piece.

Happy Turning - Tom

Don: this is likely what Tom is saying. Trace your tombstone onto a piece of thin mdf or thin plywood. Cut on that line. Put it back on top of your tombstone and, using a compass set to one inch, scribe a line on the plywood using the pointy end of the compass to follow the outside of the tombstone. Cut the plywood on that line. Now you have the pattern for your groove. Simply put the plywood back on top of the tombstone, holding it with double sided tape, indenting it 1" from the edge of the tombstone's edge. Using a bearing straight router bit, route the groove with the bearing rubbing against the pattern.

Grant,
Thank you for your reply. I've had more coffee today! Re-reading Tom's post, and yours, ( and a good head slap ) I got it!   

Len,
Thank you for your reply. Yes, my cutting guide works great for straight edges. It's about three inches wide.. and would not fit inside the radius of my curves.

Glenn Jacobs wrote on Nov 9^th, 2017 at 2:34pm:


This also determines which you might want to rout first.
If the groove is close to the edge, it may be easier and safer to cut the groove first, while there is a solid edge to support the the wood from chipping. Then you can rout the outside profile, in several passes it need be to avoid chipping. (especially when climb cutting)