First, is an Illinois model 11 fitted with a 60-hour mainspring? Second, since a Ball-Illinois model 810 is essentially an 11...does it follow it would be a 60-hour watch also? The Ball-Illinois is not marked as such, so its a bit of a mystery (to me anyway). BTW, is there a way to identify 60-hour watches other than the obvious marking? Thanks in advance for any info on this!
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