My MGB GT side flasher bases must be the light weight models that were an option on MG’s. Many folks brag about their drilled out brake rotors and drill other holes in their accelerator pedals to lighten them, why not wait for nature to do the work for you. A case in point, this side/flasher base is now lighter than it used to be, likely not enough to change the handling of the car but…
In all seriousness, I’m going to use my fiberglass skills and fill in these rusty areas, then a coat of paint and they should be ready for another 40 years of service.