Here is how I did it:

If your fingers are thicker than mine, hole and groove sizes may need to be larger. Outside dimensions will need to be larger to accommodate those changes.

- Prepare a block of wood 1-1/2” thick (i.e. face glue two pcs. of ¾” thick wood). It should be at least 2” wide x 6” long.
- Make a simple jig to rout 1” diameter x 2” long grooves, using a 1” core box bit.
- Plunge rout 1” holes (not slots yet) 1-3/8” deep (or the deepest your router will allow if it can’t do 1-3/8”). You need one hole for each hatch lid , spaced no less than 2-5/8” apart.
- Rip the top ¼” of the block off (with the 1” diameter holes in it).
- If needed, use a 1” Forstner bit in a drill press to clean up the holes in the ¼” thick strip
- Use a ¼” roundover bit to round the bottom of each 1” diameter hole. Do not round the top surface.
- On the remaining 1-1/8” thick block of wood (with dimpled holes/rounded bottoms) and the routing jig mentioned above extend each dimpled hole to 1” deep x 2” long. If your dimensions are right this will leave 1/8” thickness of wood below the grooves. That is essential to keep the finger hole blocks waterproof.
- Hand sand the grooves through 120 grit.
- Apply epoxy to the insides of each groove and to the insides of each hole in the ¼” thick strip as well as the bottom surface of the ¼” thick strip. Set the blocks upside down over a plastic sheet to prevent puddling in the grooves. This coating is to waterproof the grooves and holes. Reapply epoxy later if needed.
- Scrape any epoxy drips from the flat surfaces of each block. Sand the epoxied bottom surface of the ¼” thick strip (80 grit).
- Using slightly thickened epoxy, coat the top surface of the 1-1/8” block. Join the ¼” strip and the 1-1/8” block together. They should be aligned as they were before they were ripped apart, with each hole directly above and at one end of a groove. Clamp them together and set them aside.
- After the epoxy has set rip the block to 1/2” wider than the 1” hole (1/4” on each side of the line of holes). The block should now be 1-1/2” wide.
- Crosscut to ¼” outside of the hole (on the side that is beyond the groove), separating the block into two blocks (assuming you’re building for two hatches), each with a visible hole and a no-longer-visible groove.
- Crosscut each block to 2-1/2” long.
- Sand all edges and corners, except the surface with the hole
- Paint epoxy on all outside surfaces of each block
- Decide where a block will be mounted on the inside surface of each hatch lid. Using a 1” Forstner bit drill a 1” hole in each hatch lid in the appropriate location to align with the hole in the finger hole block
- Sand the inside surface of each hatch lid where a finger hole block will be mounted. Sand the top surface of each block (the surface with the hole). Apply thickened epoxy to the surface of each block with the hole. Join each block to each hatch lid, being careful to align the hole in the hatch lid with the hole in the finger hole block. I used a short piece of 1” O.D. plastic tubing inserted in both holes to align them.
- Tape each block to its hatch lid. If possible, clamp the block in place. I used miniature c-clamps, inserted through the holes after removing the plastic tubing.
- After the epoxy sets, sand the hole in the top of each hatch lid to remove the sharp edge. Apply epoxy to restore protection.

If a few photos will help illustrate that, here's a link:
http://www.flickr.com/photos/girer/sets/72157634814698407/