Wow - that is beautiful work, MaineSail. I am planning on installing a terminal strip behind the location where the old panel panel location.....just hope I can get somewhere in the same ballpark as the workmanship in your example!
It's not difficult stuff just a bit tedious. For making the door I use a Kreg Jig & epoxy and the hinge is a recessed piano hinge so the door lays flat against the bulkhead when closed. A router works best but a good sharp chisel can work too. I have made LOTS of teak and mahogany doors with the Kreg Jig.
Here's another opening panel with a Kreg Jig door.
For color matching the new teak to aged teak, 30 years difference above, I often use either Red Cherry or Mahogany Watco Danish Oil. Some times I blend the two to get the desired color. Usually the match is quite unnoticeable and the Watco yields a more natural aging than a "stain" does...
For terminal strips I like the AMP FlexiBlocks as you can make them any length you want or need. They are expensive but very nice.
Normally I would use heat shrink crimps but the owner felt it to be a little "overboard" for the project seeing as none of the rest of the boat has them, nor does it have tinned wire. I used AMP PIDG ring terminals with an AMP aircraft certified crimp tool.
Everything gets a number so wires can be traced and larger wires are labeled with a label maker than clear heat shrink over that.
The existing panel was in rough shape. I was able to install new LED indicator lights, all new breakers, new batt switch and completely re-wire it for about 1/4" what a custom replacement would have cost. Because of the fitment of this panel an off the shelf panel by Blue Sea, normally my first choice, would not fit.