Here's a quote from an airhead guru (snowbum - Robert Fleischer) on his site about ignition modules (ICU). http://bmwmotorcycletech.info/ignition.htm
I haven't tried using one of these modules in place of a Dyna, but it seems it should work. Dyna uses hall sensors like the airheads, it's a very common ignition system. It should mostly be an amplifier 'sensing' the hall sensor which replaces and takes over the function of points. The Hall sensor provides a path to ground when energized, just the same as points. So it's exactly the same as a points system, just smaller currents controlled electronically, and the module takes that small signal from the Hall Sensor and shoots off a large current to the coil. Here's what snowbum has to say about airhead modules:
Listed here are reported modules that MAY work OK. The word MAY is being used here, because there may be complications, particularly if you have the later 0.5 (often called 0.7 ohm) twin tower coil. It is my belief that just about any module would be acceptable for emergency use ...but may not work 100% properly, so are only recommended for emergency use. Some people carry one of these on the motorcycle, but modules don't fail often.
GP Sorensen 11-5064.
NAPA (Echlin) TP100 (supposedly from Globe Motorist, but will not sell small quantities; Napa prices were considerably higher, but worth a look/check).
Standard Motor LX501.
Wells Mfg RB100.
MANY cars use similar modules. They may not be same for logic/timing, but probably will at least function. Don't leave the key on for long periods of time with engine not started, as the internal timer may not function the same, if even present.
Transpo BM-300 Rocky Point cycle.com Also has #9604, Ignition Module, made in the USA. Has Part number 9608, Ignition Module, made in the USA, for the Classic K bikes. Also sells the Boyer-Bransden Ignition. A Microdigital ignition advance curve is later in this article.
VAG (VW and Audi) ignition module part nr. 191 905 351b is a drop-in replacement for the earlier Airhead modules.
Cars that you may find modules on in wrecking yards, or can get modules at auto-parts stores, besides what has already been mentioned:
VW Golf and Passat 1979-1989.
VW T2 Transporter and Jetta 1979-1992.
VW Scirocco 1979-1995.
VW Corrado 1979-1995.
Audi 100 1980-1993.
Audi 80 1979-1993.
Audi Coupe 1981-1994.