My big hole saw arrived, so I used it to do a test run on the cutouts for the Ta Chiao ports.
It worked well. 
I also did a test cutout for the ABI ports, which was much more challenging because the top and bottom lips slope down. I used an adjustable angle gauge to capture and reproduce the correct angle. I made a paper pattern to mark the centers for holes for the circular corner holes, which of course were different diameters on top and bottom. They had to be cut at an angle in one direction, perpendicular in another. I thought I might be able to do it by putting the hole saw in my Portalign tool, but the hole saws were too big. I used the Portalign to drill the pilot holes for the hole saws, which turned out to be adequate. I connected the holes with straight cuts using my nice new Bosch jig saw. The top and bottom cuts had to be cut at an angle, of course. A piece of old scrap served as a straight edge to guide the cut.
The results, while not perfect, were close enough to show that the method should work.
Next, I fabricated a long wooden tube or box to cover the welded iron mast support post in the saloon. This post also supports the saloon table.
First I sawed up a big board of jatoba, a Brazilian hardwood that can look a lot like teak, but costs about one fourth as much. It is often erroneously referred to as "Brazilian Cherry" when made into furniture or flooring. It is not a species of cherry. While it lacks the natural weather resistance and durability of teak, that doesn't matter for this application inside the cabin.
During assembly, I had to straighten out the resulting boards a bit, using assorted clamps as shown in the photos. 
I still need to round off the corners with the router, cut bungs and plug the screw holes (at least on one side). I'll probably also put some varnish on it before I remove one side and reassemble it around the post on the boat at some future date.I decided to take the week off to try to make some more progress on the boat, but the weather hasn't been helping. Today it cleared off and was a pleasant day, so I went to the boat and started on the major job of installing the Ta Chiao ports in the v berth (one of the patched-over old portholes leaks). In addition, it had been raining for 48 hours more or less continuously, so it had been a pretty good test for the newly overhauled and resealed forward hatch and doghouse skylight and I wanted to see how they held up. No leaks! Joy!!!
The bulk of the day was spent grinding off the giant sealant mess from where the original ports had been, beveling the edge of the 'glass cabin side to bed the new glass needed to fill the gap created by installing a smaller port, and laying in the first four layers of glass/epoxy.
When I realized how many more layers of the lightweight glass cloth I would have to lay in to build the required thickness, I left early to stop at TAP Plastics to pick up some heavy mat and more resin. I hope to finish building up the layers of 'glass tomorrow. Wednesday I should be able to grind the glass down and fill with microballoons in preparation for fairing. Thursday would have been a grind: manually fairing the filled glass to get it straight, flush and smooth using a small version of what I've heard called a "torture board." It looks like I'll get a weather reprieve, though. Rain is predicted for Thursday, Friday and Saturday. I may not get the new ports installed, but at least it won't leak!
When I'm faced with this kind of frustration, I often recall the wisdom of an old Navy engineer friend of mine. When you have to deal with a stubbornly intractable problem like this, "You just have to be more stubborn than it is." So, I'll keep re-doing it until it I'm satisfied. (Although I may give serious thought to lowering my standards.)
Although I generally avoid using 5200 because it adheres so tenaciously that it is almost impossible to remove anything you bed with it, in this case I wanted strong adhesion to insure an effective and lasting seal despite potential movement from dimensional instability. Furthermore, because all the sealant is on the surface rather than bedded beneath a fitting, it can be chiseled and ground away (again) should that ever become necessary.
I took a lunch break while the sealant cured, and afterward removed the tape when the sealant had cured enough not to leave a stringy mess when the tape was pulled, yet was not so firm that tape could not be removed. 
I cleaned up the mess, put things away, and installed temporary covers on the hatches. It had become very hot and humid, the air was stagnant, and I had sweated enough. So I called it 'good' and headed home later that afternoon.
After setting the skylight in place, I started working my way around the mounting flange from the center of each side in turn to the corners. I quickly discovered that each of the original stainless steel machine screws I was re-using had been cut off to be flush with the nuts on the underside of the doghouse roof. That resulted in each of them being a slightly different length. That resulted in some being a bit short in the place I was using them. Soooo....I had to grind off some washers that had been epoxied to the underside of the doghouse roof and get a few more longer machine screws. Of course I also broke a drill bit somehow, so had to get a replacement. SNAFUs aside, the routine was to drill a new hole one at a time, apply a bit of Lifecaulk around the top of the machine screw, screw it into the hole, climb down and screw on the nut from below. When I was lucky, I could snug up the nut; when I wasn't, the screw spun. The climbing up and down routine was repeated at least once for each of the 36 machine screws. I finally had to ask someone else to interrupt their work on their own boat to help me out by tightening the nuts from below while I held the screws in place from above. With the skylight finally secured, I just needed to trim the butyl tape and clean up the excess Lifecaulk, resulting in a pretty neat installation.
