I could be wrong but I don't think Ericson finished the inner profile of the cabinet door frame with a router. What I have seen is the traditional rail and stile shaper treatment the leaves a square corner. Very cool door though!
Another guess, and that's all it is, is that back in the distant 70's Ericson owners tended to be a bit more emotionally involved in their chosen sailboat.
A tip of the ol' EY hat/helmet to Bruce King !