Beta support: MMS on chatty/mmsd on Modem Manager - help/testing wanted!

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I'm having trouble extracting images from mms I receive. 
I don't see any notifications in Chatty (using the mm-account branch), and I assume I am launching the 'mm-account' Chatty as opposed to the Chatty that came preinstalled, launching /home/mobian/bin/chatty/build/src/chatty and it brings up a UI that looks identical to the preinstalled Chatty.

I went through the Mobian MMS Wiki, installed the mm-account branch of Chatty, installed mmsd-tng, purple-mm-sms, and verified my modem/mobile data is working.

Code:

mobian@mobian:~/.mms$ systemctl --user status mmsd-tng
● mmsd-tng.service - Multimedia Messaging Service Daemon
     Loaded: loaded (/usr/lib/systemd/user/mmsd-tng.service; enabled; vendor preset: enabled)
     Active: active (running) since Fri 2021-06-25 14:00:50 MDT; 1h 25min ago
   Main PID: 3506 (mmsdtng)
      Tasks: 4 (limit: 1950)
     Memory: 8.3M
        CPU: 1.405s
     CGroup: /user.slice/user-1000.slice/user@1000.service/app.slice/mmsd-tng.service
             └─3506 /usr/bin/mmsdtng -d

Jun 25 15:24:51 mobian mmsdtng[3506]: mmsd-tng[3506]: ../plugins/modemmanager.c:set_context() You are connected to the correct APN! Enabling context...
Jun 25 15:24:51 mobian mmsdtng[3506]: mmsd-tng[3506]: ../plugins/modemmanager.c:bearer_handler() At Bearer Handler: path /org/freedesktop/ModemManager1/Modem/1 active 0 context_active 1
Jun 25 15:24:51 mobian mmsdtng[3506]: mmsd-tng[3506]: ../plugins/modemmanager.c:bearer_handler() checking for failure
Jun 25 15:24:51 mobian mmsdtng[3506]: mmsd-tng[3506]: ../plugins/modemmanager.c:bearer_handler() No failures

I can see files in ~/.mms/modemmanager, but I cannot extract them. I followed the Mobian Wiki but am running into python errors, trying python and python3. I can't find anything pip-related to install to avoid the python3 'no module' errors.

Code:

mobian@mobian:~/.mms$ ls -l modemmanager/
total 2873
-rw------- 1 mobian mobian  728239 Jun 25 12:39 01672d6f1b3311405f1a8b41e11ce02b3173
-rw-r--r-- 1 mobian mobian      63 Jun 25 12:39 01672d6f1b3311405f1a8b41e11ce02b3173.status
                     <--- snip --->
-rw------- 1 mobian mobian   76185 Jun 25 12:37 e77ecfd316db41419e1b14c19047ea3e5d52
-rw-r--r-- 1 mobian mobian      63 Jun 25 12:37 e77ecfd316db41419e1b14c19047ea3e5d52.status
-rw-r--r-- 1 mobian mobian     543 Jun 25 13:30 extractmms.py
-rw-r--r-- 1 mobian mobian     290 Jun 25 14:00 mms

Code:

mobian@mobian:~/.mms/modemmanager$ python ./extractmms.py 2e69f61e11a47140ae1b56316714a8e48ca1
Traceback (most recent call last):
  File "./extractmms.py", line 5, in <module>
    mms = MMSMessage.from_file(path)
  File "build/bdist.linux-aarch64/egg/messaging/mms/message.py", line 266, in from_file
  File "build/bdist.linux-aarch64/egg/messaging/mms/mms_pdu.py", line 94, in decode_file
  File "build/bdist.linux-aarch64/egg/messaging/mms/mms_pdu.py", line 109, in decode_data
  File "build/bdist.linux-aarch64/egg/messaging/mms/mms_pdu.py", line 190, in decode_message_body
  File "build/bdist.linux-aarch64/egg/messaging/mms/wsp_pdu.py", line 720, in decode_content_type_value
  File "build/bdist.linux-aarch64/egg/messaging/mms/wsp_pdu.py", line 842, in decode_content_general_form
  File "build/bdist.linux-aarch64/egg/messaging/mms/wsp_pdu.py", line 653, in decode_value_length
messaging.mms.wsp_pdu.DecodeError: Invalid Value-length: not short-length, and no length-quote present
mobian@mobian:~/.mms/modemmanager$ python3 ./extractmms.py 2e69f61e11a47140ae1b56316714a8e48ca1
Traceback (most recent call last):
  File "/home/mobian/.mms/modemmanager/./extractmms.py", line 2, in <module>
    from messaging.mms.message import MMSMessage
ModuleNotFoundError: No module named 'messaging.mms'

There are also mms files in ~/.mms, but only one file is greater than 0 bytes. I think these files may have appeared when I set AutoProcessSMSWAP to true, but I'm not sure. Does anyone know where these files came from?

Code:

mobian@mobian:~$ cd ~/.mms/
mobian@mobian:~/.mms$ ls
modemmanager  receive.169I50.mms  receive.7OIG50.mms  receive.8KLE50.mms  receive.E42I50.mms  receive.H7DI50.mms
mobian@mobian:~/.mms$ file *.mms
receive.169I50.mms: empty
receive.7OIG50.mms: empty
receive.8KLE50.mms: empty
receive.E42I50.mms: empty
receive.H7DI50.mms: DOS executable (COM, 0x8C-variant)

If someone has an idea of what else I can try, that would be fantastic. Ultimately, it would be great to have Chatty fully integrated for MMS, but I understand Purism and others need to help tie mmsd-tng into their app.