This concerns only the StJV Railway Co., which operated LaGrange, IN-Columbia, OH. The track west of LaGrange was operated by the traction company side of the StJV.
The annual reports are at the state archives in Indy. It never had a profitable year. In its last year, 1917, it was $111,539 in the red (about $2 million today). It was Dr. Bucklen's model railroad, and I'm not joking. His kids scrapped it a few months after he passed.
Maps and/or deed records of the route are in the files of the county recorders in Indiana. I haven't looked at the Williams County, OH, deed records and I need to: the intent was to extend the line to either Bryan or Pioneer, and the roadbed was graded to Pioneer.
A photo of the depot at Columbia, OH, is at the Bryan library. I haven't visited the libraries in Indiana for photos.
The StJV underpass of the FtW&J RR and N. Wayne St. in Angola was constructed when the line reached Angola from the west in 1905, which was a few years before the line was extended to Columbia, OH.
Galloway & Buckley wrote a very good history of the StJV, available at the Angola library. Surprisingly, Galloway's manuscript has information that should have been included in the history.
The attached photo was taken where Sunset Inn is now located at Crooked Lake. The roadbed is still visible behind the tavern. It ran about 45 deg. northeast, through the gas-convenience store at CR200W & 200N.