Ok I put 190 in 11-19 as suggested.

BTW some of what might be going on is that this system was initially programed by another.
When i went to 11-02 only the Existing Extensions were numbered.
Port 001 is Ext 100
Port 002 is Ext 101
Port 003 is Ext 102
--
--
Port 008 is Ext 107
Port 009 is Ext 181 SLT
Port 010 is Ext 182 SLT
--
--
Port 018 is Ext 115
Port 019 is Ext 183 SLT
Port 020 is Ext 184 SLT

After that all has been cleared out up to Port 112 to Port 128 which are
at what I would guess are default Ext 413 to Ext 428.

I will try the new setting later this afternoon.

I am a bit concerned about the DTMF potentially being off tone on the SLT port.
Do you know if that Is something that can be adjusted or corrected??

Thanks for the assist!!

Les