Island A

>>>>Given that, I wouldn't expect duty stays much longer than 437 days or so
anyway. If a person is not going to stay for years and years, then I
don't see why we have to design for rotation. We know already that people
can survive a 437-day stay in microgravity and return safely to Earth. We
really don't need to make an orbital workshop any more complicated than it
minimally needs to be.>>>>

In that case, the initial SMF could be built using perhaps 2-3 external tanks.
One tank would function as an assembly hall, with an airlock at one end, while
the other(s) would be divided into small ore processing facilities, component
manufacturing workshops and crew quarters. A big difficulty that I can see is
the shielding problem.

Using a spherical pressure vessel gives us a big advantage in that respect.
The surface area/volume ratio of a sphere is the smallest of any three
dimensional shape. We therefore require less shielding and the amount of refined
metal that is required to produce the pressure vessel, is kept to a minimum.
It might therefor be a better idea, to push the ET's up to L5, and simply use
them as a source of Aluminium for the construction of a spherical pressure
vessel. Burnt out rocket stages (like the upper stage of Ariane) might be useful
in this respect.