After the Bridgton & Saco and the Sandy River & Rangeley Lakes came under ownership of the Maine Central, the railroad’s equipment was added to The Official Railway Equipment Register. This is, to the best of my knowledge, a fair assessment, as I have not been able to locate a B&SR list in Registers that pre-date MeC acquisition.
Below is a PDF copy of the B&SR equipment list from March 1914, as published in the April 1914 edition of the Register.
A complete digital copy may be viewed here. For the Sandy fans, the SR&RL list precedes the B&SR list on pg 342 in the complete copy.
Note that the sole tank car on the line at this time is #22. Review of the 1912 through 1917 Registers confirmed this was consistent and not a typographical error within a given year’s publication.
Note that most of these scans, if you choose to download a PDF version, are between 100 and 400 MB in size.