Having the buildings that provide the resource at Industrialism will still cause the problem because the old will obsolete on discovering the tech and the new will only just become available.
In my view any building that upgrades to another should only become obsolete when its upgrade is free in new cities.
I argued about this problem in Realism - Invictus. We came to an agreement.
i.e. A forge is still a forge even if something better is available. In fact a family member of mine still uses a forge to make gates/Railings etc. too repair/replace old buildings, yet keeping the original style.
In RI - we overcame this problem by discontinueing the old building by the tech that gave the new building. i.e. forge/replacement. That meant, you could no longer build a forge in a city that did not have one, but existing forges still worked. Cities with no forge had to build the new replacement.
Then at a later Tech - that gave an even better production building (second pproduction upgrade building in line) - the forge would become obsolete (you would lose it). So as a player you did not lose the hammers etc. produced straightaway. You had time to choose when to upgrade, soon or after the next upgrade.