Martin,
I’ve just purchased an A32; and the previous owner had fashioned a short hatch-board of sorts with a RADAR mounting on it. When he wanted to move the monitor from inside to the boat to face the helm, he “simply” dropped in the board and screwed the monitor to it. Not the most elegant solution I know, but it might do until you can find an appropriate pivoting unit.
Bill Hutton, BHYC, Spirit 1 (hull #15)