I'm pretty sure the thing centered in the 1st photo is an old breakaway switch (as Jim said) that's missing some parts.
The thing centered in the 2nd photo looks like it might be the remains of some sort of built-in level indicator, if the 2 channels cut in it once held bubble tubes. It looks a bit heavy-duty for a level, though.
Il Carriaggio 1975 Argosy 24 | Il Progetto 1976 Argosy 28 Center Bath | WBCCI# 15566
He has all of the virtues I dislike and none of the vices I admire. Sir Winston Churchill