FWIW, the most recent RMY auction had a Conlon image also taken at Hilltop Park c. 1910. The size is 6.5" x 9.5". It has no white border. Here is the link:
https://rmyauctions.com/bids/bidplace?itemid=51452
RMY characterizes the photo as Vintage 1, which they define as being printed from the original negative within 5 years of being shot.