I didn't want to post more ARD stuff in the performance parts for-sale section and didn't find one that applied to this so I started a new one.
When setting up my ARD mark II for testing I noticed the large replacement stem that goes in the end of the crank and replaces the stock advancer stud. There are a couple of these ARD's for sale on ebay but they seem to be missing that part. I'd guess someone bought the engine and didn't notice the stud wasn't stock and left it on the engine.
Also, a guy that posted a report online about setting up his Mark II had to manufacture that stud. Edit, I looked and my mark 1 also has a special stud there.
This particular model is self-powered with no external voltage, 12V applied to the kill switch wire will kill it permanently.
Terry and others have seen different types of Mark II or later ARD mags that may or may not need voltage but this particular one does not. I'll try to post pics of both mark 1 and II tests. My video was too big.
Edit, we think the mark II dist. cap is fiat X19, the belt is the same length as the mark 1 mag but .250 width rather than the .375 of the mark 1 .