Alec did have a lot of variations on the basic Spade pattern, it was a good fly to show off at shows but I never heard him claim origination during the 20 plus years I knew him. Considering that Alec’s favorite fly for winter and spring fishing were variations of the skunk, I wonder if the...
American Fishing Wire is another potential for you. I’ve used it for a few years, no problem tying a perfection loop in it. If I remember right they also produce Beadalon. Check out Hobby Lobby, Michaels etc.
Dying moose mane black will leave you with black hair. Look for a patch of moose mane with white hairs and you will have both colors, thats how the original mosquito pattern was tied.
Try soaking and washing one in Dawn dish detergent, it should take care of your problem, it has worked with capes that have gotten greasy that I have had. If it works, well, I see rub a dub in your future.