Share 'Henry Irving Postcards'

Hello everyone. I am new to this board. I have four postcards of Henry Irving, and eight postcards of David Warfield that were sent to my grandmother in 1906. They are in good shape. I woyuld like to see if these postcards have any value to collectors. Can you recommend any websites or specific books that might help me to determine their value. I'd be happy to send anyone scanned copies for t...