Back in the days of the old LRE forum there was a HUGE thread about their timing gears which all got terribly involved and somewhat protracted - so much so that we mods had to step in every now and again.
That thread probably still exists - it, along with others, will provide all the answers. TBH we don't really want the hassle of dealing with the intricacies and possibly legal implications again so I do not think we need to backtrack along some very worn paths on here.