Well there might be a light at the end of the tunnel for you here. Ofcourse this is merely a wild guess on my part since it can be a difficult thing to diagnose engine problems over the internet, but after reading your posts and viewing your posted pictures, I think there's a very good chance that your problems with this engine are electrical, rather than mechanical, so it's the electrical ignition items that I would focus on first if I were you.
#1. Ignition timing: many timing lights do not play nice with MSD ignition boxes since they're just not compatible. So you may need to bite the bullet and pay the big bucks for this timing light made by MSD especially for their ignition boxes.....
(hopefully these timing lights are made better and are more reliable than their ignition boxes are since 2013 when MSD out-sourced many of their products overseas)......
#2. I have those same Taylor "409" 10.4mm plug wires as you do, and as you already know, you have to use the Taylor wire looms especially for those wires, and the fact that your present Taylor wires are sliced up, might be the cause of your engine running like crap because the wires might be arcing all over the place where they're sliced. I'd replace those wires immediately before proceeding to anything else.
#3. I've never had Jacobs brand ignition parts, but it's always been my understanding that they're very different than ignition parts of any other brand, and my guess is that they might not be compatible with anything else, (including MSD). So I would remove that jacobs coiland anything else from Jacobs that you have on there, unless you want to use all their ignition products instead of the MSD. But I think it needs to be one brand or the other, and for me personally, I would only use MSD if I had I had their stuff that was made at least 7 years ago because they have gone downhill since then.
You might have other issues besides the ignition parts, but it's worth it to begin there, because you might get lucky and discover that the ignition parts were the only problem. But ofcourse a compression check, and a fuel pressure check, as well as pre-oiling the engine through the distributor hole in the intake manifold is in order. But think about it....if at least 3 or 4 of the cylinders weren't firing, or were only firing intermittently due to sliced up plug wires arcing badly, then that alone might cause lots of unburnt air/fuel charges to be flowing through those cylinders, which in turn might be the cause of fuel in the oil. Just a hunch, but one worth investigating by replacing those damaged plug wires. Either way, you need to replace them with good wires anyway. So why not do that FIRST??