Narco interconnects?

Hi All,
As posted before, I have a com 11A that I would like to get in proper
operation. I have the pinout info thanks to this group and have sound coming
from it. However, most noise is coming from the internal circuitry verses
signal from the antenna. Does someone have the interface info for tying into
the mike, phones, intercom and the like? Also, approximate impedances this
set works with?

Jim Weir mentioned that this unit can be upgraded to the new bandwidth
specs. What would this cost? Where is it done and is this something I might
be able to do? I appreciate everyone's help.

Thank you,
Jim Burns