This is possibly stating the obvious, but although the
angle of the taper on Campagnolo BB spindles is the SAME as one finds on Shimano square taper BBs, they are not directly interchangeable because the Campy's
wedge is smaller.
The GOOD NEWS is that while you cannot substitute a Campagnolo square taper BB/-spindle for a Shimano BB spindle, you can use a Shimano-compatible BB with a Campagnolo crankset.
MY experience is that an
asymmetric 113mm Shimano-compatible cartridge BB works with many Campagnolo (ISO) crank arms from the
80s ... and so, I think the same may be true for your '77 vintage crank arms ...
I would be more worried about the "salt air" affecting the anodizing on the crank arms and on the other alloy components ...
So, I would be inclined to use a different bike than your MASI for toddling down the NJ shore.
In other words, the equivalent Campagnolo spindle will be
5mm longer than a usable Shimano-compatible BB spiindle ...
So, if the Phil Wood BB has a
Japanese taper then you need to choose the length, accordingly.
MEASURE your current spindle length and choose accordingly based on whether the taper on whatever cartridge BB you chose is designed for a Shimano-compatible or Campagnolo-compatible crankset .