The unit that Sierck has modified dates back to the early 1970s, when it was a kit. Apparently in Europe, it still is a kit. There are better parts to use today, but the old ones will still work just fine, if someone wants to hand-build one like he has! Good for him!
Terry: which Dyna coils do you have? Are they the "green" ones? And, what spark wires are you running, are you using resistor caps or resistor plugs?
Reason I ask: while I'm waiting for the circuit boards to arrive, I can test a setup similar to yours ahead of time. I have some "green" Dyna 3-ohm coils. They should be run with either resistor spark wires or resistor plug caps or resistor plugs (at least one of the above) to generate best peak voltage. I'd like to test with your setup here first so there won't be any unusual surprises.