I’m going to develop a reference chart of component / system features that are characteristic of the time period of construction. Before I do, has someone already done this and willing to share or have thoughts of how to organize the information. I’m debating to categorize by date ranges or by systems.
I know there will be overlap but in general it might be a handy reference chart to add to your collection.
Rating 200 > 1980
Service Lead < 1950
DWV Cast < 1960