These two brackets/gidgies appear to have been screwed to wood, it follows, given their size, the wood would have been significantly larger thus offer positive buoyancy and facilitating their dispersion across the lagoon. It is therefore very possible that these brackets/gidgies came from the Norwich City.
It's possible, but previous analysis on EPAC didn't seem to point in the direction of the Norwich City, a British-built freighter. In 2002, A British researcher observed the gidgies appear American in origin.
"The nature of the plates make it virtually certain that they
were amateur made and used American screws...
The thicknesses are reasonably consistent with an American origin, either
Brown and Sharpe gages or "preferred thickness" gages. The thicknesses do
not tie in so well with a British origin as this would mean an SWG (Standard
wire gauge) thickness which lies in both cases just outside the maximum and
minimum thicknesses. It has to be said that the variation in thickness over
the plate makes a nominal thickness difficult to be certain of or even if it
is relevant, but ... The American gage (B & S) of the plates would be 17 (0.0453) and 19 (0.0359) .
Equivalent preferred thickness would be 0.036 and 0.045."
He suggested the LORAN station as one probable source but neither did he rule out the hypothesis that it was for a modification to a sextant box.
Joe Cerniglia
TIGHAR #3078C