I'll share this for folks that want a down-firing light.
I built these fixtures and lamped them with either 36-SMD LED or 48-SMD LED panels bought from E Bay. They came with adapters. The fixtures I bought at the dollar store and are made for business card frames. I cut a piece of light aluminum sheet that becomes the mounting surface for the LED panel.
Process: Lead wires out of paneling, solder on molex connector, fasten light aluminum sheet piece to ceiling or wall, attach LED panel and connect to wires, slide card holder fixture w/glass lense onto aluminum sheet piece.
The above fixture was an after thought so wires are lead on surface. All my others have the wires under the paneling and for some, I wired in a small toggle switch. I have had no panel losses, no heat issues, and the 48-SMD panels in Warm White are very close to the output of the original incandescents they replaced.