Couple of thoughts:
Did the scope test actually say you have a dead cylinder?
I'm trying to understand the low compression on #8. Has anyone done a leak down test on that cylinder? What did the compression do with the wet test in the compression check? Did the presure come back up to the same as the rest of the cylinders? Low compression has to pretty much be gasket, valves or rings. If you have been running real lean on that cylinder, you could have a burned valve. (btw, has the engine had valve seals done?) What did the plug look like that came out of there?
Have you tried running a few cans of Chevron Techron thru your tank? I would double or triple the dosage just to see if it will help. Can you switch the lines for #7 and #8 at the fuel distributor without damaging the lines? Might be interesting to see what that does. Just don't leave it that way.
Another thing to try: Be careful on this one. May want to have friend on hand with fire-extinguisher. With engine not running but fuel pump on, remove the fuel line from the injector and point it into a small container. Press down on the sensor plate for just a second. See if any fuel comes out. Note: there will be fuel running in all injectors so the rest is going into other cylinders and eventually the oil. You may get some fuel out this way, but maybe less than the other cylinders.
Finally, if you do have to replace the distributor (and does kinda look that way) maybe get one used from a salvage yard? Those things normally go for a very long time and I would expect one from a recent arrival at a yard to be fine. and maybe a lot cheaper