What I found when I was last there a year and a half ago was this.
The 450 mhz.analog LTR system was still in use with all talkgroups active except security. I found security using one of the LTR freqs. in the DMR mode exclusively and 100% encr. It was 451.875, CC 1, and TG 20. UID's were in the 19xxx range. I don't know if that freq is still active but you may want to check 451.875
Bob
Milford, Ct.