Indiana State Police had several short films produced over the years. ISP cooperated in two films featuring VASCAR and can still be found on youtube. I believe these were actual Troopers in the film and the tele-commincators looked to have been in a old ISP radio room. When I grew up in Southern Indiana in the 70’s the District PIO (Public Information Officer) had a radio number of 35-XX and nothing special unless they were a Sgt. with a lower number like 35-6.
The only Trooper I ever heard with non typical radio numbers were assigned to special duty out of the area headquarters or out of Indianapolis. It’s possible the 1B 77 number was the actual Trooper depicted radio number and he worked out of the Superintendent‘s Office or media/video section. ISP had numerous training films produced during that time period.
Here are links to the two VASCAR videos, first is from the mid 60’s and the second on VASCAR Plus from the mid 70’s.