One for any wheelgun historians out there?

[BCCL]

I'm trying to find information on what revolvers where the standard issue for the Illinois State Police, prior to their switch to the Smith & Wesson 39 9mm in 1968.

Done just about ever google search I could try and came up empty????

 

[MikeJackmin]

I bet these folks would know:

http://www.isphf.org/

 

[MikeJackmin]

In the late 50s they had some K-38s:

http://smith-wessonforum.com/s-w-hand-ejectors-1896-1961/87896-il-state-police-k-38-a.html