Some history of the National Cloak and Suit Company suggests that the firm was founded in 1888 and changed its name to National Bella Hess in the 1920s, so the overall period of perfin use would have to be in that window.
I also found this excerpt from a NY Times article on the creation of Parcel Post interesting, suggesting that the National Cloak and Suit Company expended more than $600,000 with the Post Office in 1911 (which is the equivalent of about $15 million in today's dollars) -- it seems they were right up there with Sears and Montgomery Ward in terms of their mail order business.

The entire article can be found here:
http://query.nytimes.com/mem/archiv...9C946096D6CF