I found the posting reference here: 

http://maryannhorton.com/usenet/010180.MAP.jpg
https://utzoo.superglobalmegacorp.com/usenet/news005f1/b12/net.general/1501.txt

http://maryannhorton.com/usenet/032183.BBM.jpg
https://utzoo.superglobalmegacorp.com/usenet/news004f1/b11/net.news/541.txt

http://maryannhorton.com/usenet/040581.MAP.jpg
The map is mentioned in here: http://www.ais.org/~ronda/new.papers/articles/earlyversion.arpanet.txt

As far as BBM files I just find this:

  Name:     Graphics Display System (GDS)
  Purpose:  Image display, conversion, thumbnail catalogs
  Version:  3.1e
  Author:   Photodex Corporation <photodex@netcom.com>
  FTP:      ftp://ftp.netcom.com/pub/ph/photodex
  CIS:      GO PHOTODEX, GDS Viewing Software (Lib 3)
  Imports:  ANS (ANSI text), BBM, BMF, BMP, CUT/PAL (Dr. Halo), DIB, DL,
            FLC, FLI, FLX, GDS, GIF, GL, HAM, ICO, IFF/ILBM, IMG, JFI,
            JPG (JFIF), LBM, MAC, MP2 & MPA (MPEG Audio), MPG, PCC,
            PCX, RAX, RFX, RLE, SC? (ColoRIX), TGA, TIFF and TXT (text).
  Exports:  ANS (ANSI text), BBM, BMP, CUT/PAL (Dr. Halo), GDS, GIF,
            IFF/ILBM, IMG, JFI, JPG (JFIF), LBM, PCC, PCX, RAX, RFX,
            RLE, SC? (ColoRIX), TGA, and TIFF.
  Features: File viewing, batch conversions, easy thumbnail catalog
            creation with many options, slide shows, automatic
            configuration.  Includes 5000+ lines of hypertext help
            and prints 98 page cross referenced manual.  Supports HGC,
            CGA, EGA, S-EGA, VGA, SVGA, XGA, TIGA and VESA. Registered
            versions print to HP PCL & 100% compatible laser and inkjet
            printers.
  Comments: Used by CompuServe sysops to catalog over 40,000 images
            regularly.  ASP approved shareware.  

No idea if it survives at all.

If you can screen shot the headers of the posts it’s easier to find them in old usenet archives.  The UTZOO stuff is an AMAZING resource.  It’s been incredibly valuable looking for old stuff.  Of course the real fun is in searching it. 

Feel free to wget the BZ2 files from:
https://utzoo.superglobalmegacorp.com/

Just don’t spider into the /usenet directory as it’s all the files extracted and you’ll no doubt be pulling several million files… much easier to get the .tar.bz2 ‘s.


From: Mary Ann Horton Gmail
Sent: Monday, June 24, 2019 8:40 AM
To: tuhs@minnie.tuhs.org
Subject: Re: [TUHS] Floppy to modern files for Usenet maps

I put the screenshots (literally - with my phone) here:

http://maryannhorton.com/usenet/

Note the preposterous claim that the 4/15/81 map is the "Backbone" - I 
have no idea where that came from. The backbone was first proposed 2 
years later. Clearly this is a full map of Usenet as of 4/15/81.

     Mary Ann

On 6/23/19 4:57 PM, Grant Taylor via TUHS wrote:
>
>> I took some photos of the screen with the earliest maps (the ones 
>> that fit on one screen.) So it's an option to type things in, at 
>> least for the early ASCII ones.
>
> I'd be interested in seeing them.  Do you have a place that you can 
> upload them to?
>
>
>