I'm so sorry I somehow managed to miss your query until now. I've been fascinated by the Susquehanna and New York since I first learned of the line while attending jr. college in Williamsport in 1971. I found a copy of Edward L. Kaseman's book on the S&NY in a department store in downtown Williamsport. My first job after graduating in 1973 was in Towanda, the northern terminus of the line.
Here's a link to a little "photoessay" on the S&NY of photos and memoribilia from my meager collection that I posted at another website:
http://forums.railfan.net/forums.cgi?bo ... 1176941950
I've seen a lot of S&NY photos, as well as copies of Kaseman's book, show up on eBay frequently. Some items I've been seriously outbid on so there are others out there that have an interest in the S&NY as well.
Two pieces of S&NY equipment survive today, 2-8-0 #116, built for the S&NY in 1916 was sold to the Meridian & Bigbee River Railroad in Mississippi and eventually ended up at the Jimmie Rodgers Museum, also in Meridian, MS.
Caboose #15 was sold to the Arcade & Attica in Arcade, NY.
Regarding the book by Kaseman-there have been 3 printings of the book. The first came out in the 1940's, not long after the line was abandoned in 1942. This book, largely unchanged, was reprinted in the mid-1960's.
EDIT Jul. 22
A little digging through my "archives" this evening reveals that the first printing was in August 1941, 9 months BEFORE the line was abandonded. The second printing is from 1963.
Kaseman expanded the book in the 1970's for the 3rd and 4th editions to fit the format of the series of books then being printed on the Logging Railroad Era of Lumbering in Pennsylvania. The 4th edition has a dedication to Steve Van Gorder who took many photographs of the line but is largely unchanged from the 3rd. This book shows up on eBay from time to time.
EDIT Jul. 22
The 3rd edition was printed in 1979. Actually there was no 4th edition, the 4th printing
(which I believe was the final one) was in 1990 and was dedicated to Mr. Van Gorder who died in 1986.
Additionally, if you can find a copy of Bill Caloroso's book on the Pennsylvania Railroad's Elmira Branch there's a chapter devoted to the S&NY there. (I've been looking for a copy of this book myself. It's out of print and prices are astronomical!)
An issue of Trains Magazine from 1941 or 1942 had a long article on the S&NY, will provide details later.
EDIT Jul. 22
It was the January 1943 issue, a thoroughly enjoyable read.
PS-I'm writing from work and am going on memory-some small details may have been "misremembered"-I'll proof this entry once I get home and can get a hold of my reference material.