I met my friendly local pest control man out on site and had him spray all the e-beams with termite repellant.
I returned to site and painted the e-beams with an oil based primer - the intention is to preserve the termite treatment while the beams are exposed to the rain for about 4 weeks (before they get covered up with cladding).
Rest of the Week
I gradually started working through 4 steel beams, removing dags, converting rust, trimming the ends. These will support the corners of the bay window frames and prevent them bouncing as anyone walks across the veranda.