Went to the fly shop today, could not find any squirrel zonker strips so I did some experimenting with materials I had at home. Used rabbit and beaver zonker strips to tie up some Slump Busters. To get a thinner zonker strips I used a razor to halve a zonker strip down its length. Worked wonderful. Worked even better when I made the strips for the "wing" thicker than those for the collar.
Now I can use some of the rabbit zonker strips I have! Must have about 12 different colors of the stuff.
Alberto