Sorry for the late reply, was away for a couple of days...
you´re more than welcome - I suppose your estimate is pretty
correct. 1930´s sounds good. Hard coal will work fine, cleaning
the stove might be a bit more work than with other fuels, but other
than that I seen no problems as long you keep the lining in good
Good luck with your heirloom (was a heirloom, right?!) and stay warm!