The following is based on Fallout 3 cut content and has not been confirmed by canon sources.
Wanda is a unique R91 assault rifle found in the object database. In-game, it is functionally the same as the Xuanlong, with the exception of being more easily repaired. It can be repaired with other R91 assault rifles.
This weapon exists in the game files, and can only be obtained through console commands on the PC version. The gun is inside the mailbox marked "weapons" within the testing hall that is accessible with console commands (coc TestQAItems).