For those interested in collecting state revenues, the link to the State Revenue Society website:https://staterevenue.org/
SRS dues are only $17.50 a year. The SRS has a quarterly newsletter and hosts an auction most quarters for members only. The annual dues are a bargain!
Collecting NY Stock Transfers is more difficult than you may think. There are several series and varieties, to include the usual proofs, specimens, double transfers, imperfs, etc.
Kurt Lange's website (listed in John's comment) does a great job of illustrating them, and he has album pages for sale for those who would like to pursue these omnipresent stamps!