, I'd be very interested in seeing photos of the liner removal tool you fabricated!
I tried to tap the liners out from the bottom without much success. There's not much of a lip there to push against. I was concerned about scarring up the block and liners by using a metal rod, so I tried a large wooden dowel. The liners didn't budge, and it just chewed up the edges of the dowel...even with periodically shaving the end off with a miter saw, I didn't make progress.
I ended up using a method I found elsewhere on AlfaBB (I don't remember which thread). Working from the top side of the engine, I took two of the copper exhaust manifold gaskets, bent them into a U shape, and slipped them over opposite sides of the rim of the liners. I then took two Vice-Grips, and clamped them over the copper gaskets.
After soaking the bottom seal area of the liners in WD-40, I started applying back-and-forth pressure, and was eventually available to wiggle them free of the block. The copper gaskets keep the Vice-Grips from scoring the liners, and would have let me re-use them if not for other issues that made me want to replace them in the first place. You've got four copper gaskets to work with in case you need to change them out, but I was able to use the same two to remove all four liners.
The rubber liner seals were still in good condition when I removed them, but had been permanently reformed over time, and I wouldn't have been comfortable trying to re-use them. The mating surfaces of the block and liners had a bit of tarnish on them, but weren't corroded or anything.
I'd have to go back and re-read my posts, but if memory serves, I didn't use any additional sealant during reassembly. I cleaned those areas of the block, put the seal on the liner, shot some WD-40 on both components, and installed the liners. The seated height of all four liners checked out okay with the height of the block. Now, almost a year later, everything is still good...no water in the oil, etc.