[R-1051] USCG R-1051

[Richard M. MC Clung]

Supposedly the USCG had a modification for the R-1051 that
allowed for switching a wide and narrow filter for CW
operation.
It is a PCB with two TO-5 relays, 2 collins mechanical filters,
and some other components. It's easy enough to backward
engineer but being the anal retentive type when it come to
documentation I'd still like to get all and any "official"
documentation on this modification.
 Anyone out there have anything on this.....?
RICH  WA6KNW