mile-ender said:
Well...I'm gonna check this as solved - but I'm not necessarily convinced - no offence

If you check out this link -
http://books.google.ca/books?id=-rH...lt&resnum=9#v=onepage&q=button shanks&f=false - check the shank images on page 52 then read page 64 for the explanation.
I'm just a stickler for proof. So if anything else comes up in the future on this one or my Louis the XIIII -
http://www.flickr.com/photos/71319526@N00/3206261301/ - and the front -
http://www.flickr.com/photos/71319526@N00/3207104198/ - I'll let you all know.
There's one point you may be missing.
You probably agree it is a coat of arms, which means most likely it was a general service button, and general service buttons were always used in great numbers. Having been used in great numbers, they turn up as finds, and are very well documented. Can you now see the conflicting aspects of your find? Eventhough I can't tell you what it is, I can tell you what it's not as far as being Colonial period is concerned. I'm glad you found it though, made for a good thread.
Your 1742 H 2 Sol was very widely counterfeited. (why I asked about the stars)
Seen on your link the 104th... Great find with Incredible history! Was this dug in Montreal? Were they there? I have both a Silver officer cuff size, and a bit larger pewter. I consider myself very lucky to have found both here.
The Roman type button shank looks modern as does the face, I have seen similar buttons.