Brinks labels are listed in Bruce Mosher's
Catalog of Private Express Labels and Stamps.
Your labels appear to be BCCX-S60 and is listed as issued "1908?" (Monroe St address, magenta 10, perforated). They were positions 7, 8, and 9 on the sheetlet of 10 stamps. They have a value of $45 each in the catalog (but they are listed as having been printed "Grey on white" and yours are certainly no longer white, not to mention the tears and folds).
You can also go to Eric Jackson's site and look them up:
www.ericjackson.comEnter "Brinks" in the search box and hit submit.
You'll see other examples from his stock.
Hope that helps.
Chip