Heat And Irons
By the late 1970's or so many things about ironing had changed which were reflected in the irons one purchased.
As steam ironing of man made fibers mostly replaced dry ironing of damp cotton or linen there was a reduced need for very hot irons. What was required was enough power to turn water into steam at all temperatures. Some irons only would produce steam at settings of "wool", 'cotton" or "linen".
Since more and more women and others were working outside the home and or to make the task of ironing less of a drudge irons became lighter. This was also a reflection of modern plastics and other materials replacing metal/chrome and what not that made those heavy irons of the past.
Regarding weight of irons. Proctor appliances back in the 1940's IIRC either did the study themselves or perhaps funded one done elsewhere that disproved a heavy iron was required for good ironing results. All that was required is for the iron to have the proper amount of heat (usually generated at around 1000 -1400 watts), and that would do the work. Also steam in addition to damp ironing or in place of gave better or good as results for most work as dry ironing with a heavy iron.
Women coming out of the "sad iron" era where those items were made of cast iron naturally took some prodding to adapt lighter irons would work as well as heavy ones, but sooner or later everyone was onboard.
Have or had several Proctor, Proctor-Silex, Mary Proctor irons and they all work a treat.
Regarding the soleplate shown above, don't think the pitting and other damage can be "cleaned" off. However flePay is full of NIB Proctor irons from the 1960's through 1980's so if you like....