When I worked for the FAA a long time ago,  I fielded all the SWL or I guess SWLF reports on the NDB's that were sent to the field offices I was stationed at, JAX, FLA, 1 station, JAX:   Greenville, Greer, Spartanburg, SC which covered 3 NDB's at Greenville (GM) , Greer (GS)and SPA (FRT).,  and Asheville, NC,  2 stations,  IM and  BRA.  I  had a nice certificate to print out that  I would return to the sender..  I would get at least 1 every winter.  Back then just about every field office had a ham that did this and sent out confirmation, but today I do not think it is done, primarily because a ham in my occupation is rare today, and those who are left are not aware of what the signal report is, so the request gets rotary files.  Interesting to note, that the number one signal report station was GM,  right next to the Greeville  baseball stadium alongside a 4 lane highway, basically located in the drainage ditch on the west side of the road.  .  That staton ran 25 watts at that time to a 50 ft vertical wire topped with a 50 foot single wire top hat.  All other stations ran 400 watts from towers ranging from 100 to 200 feet except GS which had a 50 ft vertical wire topped with a 3 wire top hat, 100 ft long.  Most statons had a 120-140 county buried #6 counterpoise that only ran to the perimeter of the property.  Exce[pt for FRT and GS, all the staions are still on the air.  At the first of my career, the transmitters were art-dco works of art, with chrome accents, and dials that turned big chrome pointers.  At the end, they were all Nautel solid state units the size of a small 2 drawer filing cabinet, that contatin 2 to 8 50 watt power modules to accomodate 50-400 watts out, modulated 90% by a CW ID.  Some used to run a 10%ID and 80% TWEB voice, Transcribed Weather Broadcast, and controllers could still talk over them on some, but the TWEB is now on VHF with just the ID on LF.  A 3 letter ID indicated an LOM, Locator Outer Marker, NDB co-located with a 75MC outer marker, and used to be the stations that sent out the A and N signal, that when an aircraft was dead on course, the A and N combined to give a steady course.tone.  The 2 letter ID indicated a stand alone non directional beacon, the ID assignments did not change if an LOM went to just an NDB.  I also still listen for the signals using RAX, RCE, R390A with a Palomar LF converter, plus a 353 and a couple old marine direction finders. The best time to listen is during a power outage that covers a large area, and using a battery set, you can hear many signals even at noon.  How quiet the bands get during a large outage must be what it sounded like decades ago. ,

Charlie, W4MEC, in NC