Have been working on the SL100 as time allows, trying to decipher the wiring and finally realized the reason the prior owner and his friends could not get the bike wired or running. It had an AC coil instead of the correct DC coil. It had been at a small shop for a fresh bore and piston and the owner went out of business, returning the bike in non running condition with an assortment of parts and evidently gave them the wrong coil.
I ordered the correct coil, put it on, and the wiring began to fall in place and it now has spark. The carb is in pretty rough shape, had a broken drain screw lodged in the bowl so I tried a bowl from the SL350 carbs and it was a perfect fit. Put some fuel in it and it runs (although a little rough) but at least now I have a starting point.
My daughter has also spent a few hours rubbing and scrubbing the many years of accumulated grime off of it and it is starting to look a little better.
On the SL350 front, I have a pair of new 30mm Mikunis coming from OC and found a 1974 Yamaha rear wheel that fits and will give lighter unsprung weight, have many other ideas and am getting excited to tear the bike down and get started on a thorough overhaul for both reduced weight, more power and a little cleaner appearance. Stay tuned.