FYI - Mil Spec printed circuit cards have been using an clear acrylic overcoating that is refered to as 'Conformal Coating' for years.
The purpose of this coating, which (for all practical purposes) is a paint finish, is to maintain a moisture barrier, so that any water that condenses either on the adjacent structure/chassis and drips onto the board, or collects in pockets on the circuitry, will not bridge a wire or circuit trace and cause a short or stray signal.
The three major concerns when performing the coating application are: First - not use a conductive pigment material (use a clear) which will defeat the purpose of the protective jacket, Second - fully and properly mask the pin interfaces so you don't get a layer of paint in contacts that would insulate the mate interface, and Third - leave heat dissipation devices free of coating so that the active air can remove heat from the heatsink/coldplates.
Looks like you did a good job of meeting the Mil Spec criteria, whether you knew it existed or not.
Congrads on a job well done.
Give the Rookie a Cookie, Wookie