https://wireless2.fcc.gov/UlsApp/UlsSearch/license.jsp?licKey=1182917&__newWindow=false
33.94 153.83 154.265 154.355 154.22
1960s - 33.94 was the only channel iirc - somerville was on 33.86
1970s - 154.355 was the only freq - plus 154.22 as mutual aid
153.83 and 154.265 maybe got added at some point - maybe not - 153.83
is nationwide ht channel ish and 154.265 used to be Boston Ch 4
would not be surprised if they stopped using 33.94 in 1973
would not be surprised if they stopped using 154.355 154.265 154.22 in the 1990s