I haven't missed it. Mine was a Raymarine ST-40 bidata that gave both speed and depth. The depth function still works fine so I haven't taken the instrument out. I find that GPS speed and looking at lobster trap floats does it for me for speed and current. I don't have a wind instrument, so don't have any reason to be concerned about true wind.

As far as filling the hole goes, I like the port idea. You will never be able to get a perfect match on your yellowed mahogany if you put in new wood. Next time you stip the varnish I reccommend staining before you revarnish so the mahogany won't yellow as badly