Ed, Thanks for the kind words. The 3300 didn't usually have frame numbers. The 2200's I believe might be down by the centerstand someplace, but I don't have much info on the 2200 frame numbers. If you can give me seven digit motor serial numbers for your 3300 and 2200, or any other Solexes, I can give you accurate dates.
Here is a page that I translated about the Micron that you might enjoy: http://cyclo60.myouebe.net/Micron/Micronen.asp You'll see that they also used motors in the 5 xxx xxx range just like most of the 3800s that were sold over here, and this is very confusing for people trying to determine the model and date of manufacture.
If anybody needs instructions for setting the timing like Ed mentions, just let me know.