Nagra T-Audio - Advice Needed

We have come upon a Nagra T-Audio system that we're currently in the process of gathering information on. We're waiting for official information we've requested on this unit but due to its age and nature, it could take some time to know for certain.

If anyone is able to give some suggestions as to what to do with this, what it might be worth, if it seems to be missing anything or the best way to go about testing it out I would certainly appreciate any help or feedback from someone more knowledgable about these than what I've been able to dig up so far.

What we have:

T-Audio Main Unit with Lid
T-Audio TC Keyboard
TA-TC Taco-D Time Code & Pilot Sync Monitoring Module
TA Taco-M1 Monitoring Module
TMU Mobile Unit (Rolling Rack)

What we've been told so far by an official rep:

They believe it's a Nagra T Time Code but with the older keyboard.
Load with 3 Speed 7 1/2, 3 3/4, and 15 IPS NAB EQ and one 30 IPS AES EQ
High Stability Time Base (Option)
Serial I/O (Option)

What we suspect:

I believe from the information I've been given it is the NTA-2TC – SMPTE Time code model
loaded with options that later became more standard. We are uncertain however one of the cards does indicate the SMPTE Time Code though others we've seen of this model do not seem to have the Serial I/O.

What we know:

Not much. This unit was stored away in a studio attic and forgotten about. This unit was found during a project to clean out this attic that had no elevator access and has been in storage for a very long time.

Here's a link to my dropbox folder with pictures of the unit.

https://www.dropbox.com/sh/zutfp0awccs7xqn/AABPlhXSk2VnpdaqVow8MaRSa?dl=0