Well good to hear it si going in the right direction and you haven't taken a .45 cal to it yet. Also commend you on taking the start to people that deal with them all the time. More people should look into old time starter and alternator shops if there starter is going bad. For the most part these shops can rebuild any starter for allot cheaper than one can buy, a good amount of times, where someone will throw a few hundred dollars at a new starter, taking it to the starter shop will cost you under a hundred and get you right back up an riding.
The same goes for if you have stator go, out. Instead of spending big bucks, it may be worht sending to a specialist and many times, if the damage is not pyshical, they can rewind, better even for less than half the cost of a new one.
On the seal, yes some of the 05 and other had an issue with the primary leaking by the jackshaft and into the starter. Had it happen on my first one (whihc at the time BDM replaced with new). Also BD used to have a kit to rebuild it wiht a proper seal (some where I had a post on that years ago), but has Raywood said, getting a bigger o-ring seems to help. So continue to do search on here and you will find many many threads on most any problems along with suggestions over th years.
Once again Kudos to you for taking the starter to a rebuilder, have to shake my hand many times at the money that is thrown for new starter where in many times, a simple rebuild by a specialist will do jest as well and cost allot cheaper.