While Henry Altemus (Company) were publishing books, Altemus & Co. were printing various other types of documents.
Here is a prime example. This certificate is for shares in the Peoples National Bank of Norristown. It is relatively common as I have seen several of them over the years. If you look closely, you can see the Altemus & Co., Inc imprint on the bottom left. The ones I have seen range in date from 1897 to 1915.