I remixed jason51873's Mount so that it would fit my Manfrotto Head (MH293A3-RC1) too. Ours use the same camera plate, but a different locking mechanism. All credits go to him for his nice model, saved me hell of a lot of work! Just added another version, which offers the place for a standard GoPro-mount-nut. It should be more comformatble to handle this way. I have not printed that one yet, though!