That's why Wil Tirion put out a Double Star Atlas, to help people just like you who want to see all these double stars. On the charts he has all those catalogue numbers that are not usually printed on charts. Its not cheap (a good star atlas never is, alas) but well worth it if you're interested in double stars.
The capital sigma is for the elder Struve's catalogue and the S is for James South, apparently, a contemporary of John Herschel, who's own catalogue is the small 'h'. The Cambridge Double Star Atlas has all this.
