You should take a look at the Trinadad and Tobago aircraft made by
(senior moment... what's the name of that French company???).
They have this feature for accessing the instruments.

Jay Honeck wrote:
Wouldn't it be awesome if someone came up with an STC'd Cherokee panel
that had a piano hinge at the bottom, so that we could simply flip the
panel down, and get at the back of the radios, instruments and
switches?
Is there some reason this hasn't been attempted?