Not of The Galaxy, no one really knows where TXC-973A came from other then Courage Stacks, the droid's former master. With Stacks dead, however, no one was aware that the droid came from the Kingdom of Jod.
Lost & Found
TXC-973A was assigned to a Naval Reconnaissance Trooper (NRT) detachment under the command of a HRI Outside Galaxy Branch agent (OGB), which was assigned to 3 HRI Deep Cover Agents (DCA) on a mission in the Outside Galaxy. While details are highly classified and even fuzzy in what information they show, it is largely believed that the mission was to verify, capture, and then sabotage information at Kuat Drive Yards regarding the Resurgent-class Star Destroyer and then later Sienar Fleet Systems with the TIE/fo Space Superiority Fighter. The mission also targeted the Imperial Department of Military Research and purposed new Stormtrooper armor.
If any parts of the mission even remotely succeeded, it is largely unknown. The NRTs & OGB's Sentinel-class Patrol Craft was destroyed somewhere on mission; whether this destruction was intentional (attacked) or mechanical failure, is unknown. All crew were killed aboard, with 973A being the only survivor, floating among the debris undetected. Somewhere along the line, Courage Stacks found and rescued the droid from a junk dealer. The droid was heavily damaged.
Damage & Effects: the pathway to the Kingdom
TXC-973A's droid brain was heavily damaged. If not for the FSD Chip, no data would be recoverable. While Courage Stacks never knew of the FSD Chip, Jim Palso was able to find it with the help of Bugger and the mercenary-turned-smuggler was able to locate the Kingdom of Jod.
The damage to Walking Library's droid brain caused the droid to have an interesting personality matrix afterwards, oftentimes mixing his repair abilities with those of being a philosopher. As such, the droid had gained the ability to collect useless information he found interesting, be a rambler in conversations, and be skittish (many people compare him to the famous C-3PO's personality).
Technically speaking, Walking Library is a TXC-170 GMB Repair Droid, the GMB standing for Government Market Body. Aside from the standard programming of the model, TXC-973A has the Planetary Enforcement & Customs Agency specialty programmed, as well as having a top secret addition of both the Maritime Coastal Defense & Rescue Agency and the programming of the Military Market Body (MMB) as well. The droid brain has been heavily updated to handle this increased data and the processing power needed to function correctly.
It is believed the House of Royal Intelligence had added the additional programming and upgraded droid brain, as to why, those reasons are largely unknown and heavily classified.