In the comics Steve Dayton became Mento to meet Rita Farr who was publically a member of the Doom Patrol. They later were married and adopted Gar Logan aka Beast Boy of the Titans.
Rita says she had been an SOE spy. During WWII the British Special Operations Executive sent secret agents behind enemy lines into Nazi occupied Europe. These real life James Bond types gathered intelligence, committed sabotage, and supported local resistance groups.
In the comics, Steve Dayton (Mento) was a member of the original Doom Patrol, albeit a new recruit of that team. Josh Clay, Rhea Jones, and Arani Desai (Tempest, Lodestone, and Celsius respectively) were members of the second Doom Patrol, brought together by Arani to find her husband Niles. In the show, the order of the two teams has been switched, with Arani's team being the first (along with Dayton) and Rita's team being the second team.
The Brain's housing is shown off by Steve Dayton when showing off the trophies to Rita. Dr Fates helm can also be seen on the shelf