Chandler IN is a small town in SW IN just east of Evansville on IN Hwy 62. I drive through there periodically on business. On the way through I have seen a signed for a custom gunsmith shop--open by appointment---on the main street. That part of IN had a lot of Germanic settlers and there are still a whole lot of Germanic place names and familial names in evidence.
If the arm were mine I'd spend some time in google and other searches. You might simply google search the last name and Chandler IN and get lucky. Also check local directories for the last name and make a few phone calls. If that gun smith/shop is contactable, call and see if the name rings any bells. { Edit: I just did a real quick a dirty search for the gunsmith shop try this
(You need to Login or Register to view media files and links) I imagine the rifle was used in local small bore matches. Evansville, is a major city---one of the five largest in IN and I am sure they have a historical society. I strongly imagine there may have been small-bore and 3 position clubs and leagues in the area. The local college may have had a team as was common in those days . Local newspaper sports pages from the late 40s and early 50s often regularly reported match scores. i can remember them form my youth.
Other towns within an hour or two of Chandler include Jasper, Tell City, Washington, Huntingburg, Rockport---all with strong German settler connections. There are also several good sized towns across the Ohio in KY, and there were a lot of ferry's in those days.
UNfortunately in my travels and searches I have found that most of the German settlers in that region were from the earlier pacifistic agrarian immigrant wave rather than the middle class and artisan wave of the 1830-/40's that brought the formal "schuetzen tradition" to the US. However since your rifle represents a later era and style of competition that should work to your advantage