Hi Pat,
 
Although the date of your coin clearly predates your historic occupation, why
are you assuming that the object is not related to that occupation?
 
First of all, silver coinage was extremely scarce in the early nineteenth
century and coins of many origins were commonly being used, certainly
including at least British and Spanish examples in the Midwest.  Your coin
only predates your site by 30 years or so.  That would appear well within the
range of contemporary usage.
 
Second, I'm not convinced that Native Americans were the only folks punching
holes in coins or wearing them suspended from strings.  Within the past
decade, I recovered a punched, early nineteenth century German coin from a
farmstead site near Flint, Michigan.  For me, the most logical interpretation
for the artifact was as an immigrant keepsake.
 
Just a cautionary... but I think the assumption that any punched coin
represents Native American decorative use is too general.
 
Later,
 
Mark C. Branstner
Great Lakes Research Associates, Inc.