The book I quoted was has an actual copy right date of 1984. Another textbook that is copy righted 1977--Property Assessment Valuation by the International Association of Assessing Officers has the following definitions.
Effective Age--Effective age is the number of years indicated by the condition of the building. If a building has had better than average maintenance, its effective age may be less than the actual age; if there is has been inadequate maintenance, it may be greater. A fifty year old building may have an effect age of twenty five years due to rehabilitation or modernization.
Remaining economic life--Remaining economic life is the number of years from the date of the appraisal to the date when the building becomes economically valueless.
Total economic life--The total economic life is the estimated period over which it is anticipated that a property may be profitably used. This may be described as the sum of effective age and remaining economic life. Total economic life can never exceed, and is generally shorter than the physical life of the property.
Another text book going back to 1946 and updated several times up to 1983--A Guide to Appraising Residences by H. Grady Stebbins, JR.
Effective Age: This is the "age of a similar structure of equivalent utility, condition and remaining life expectancy as distinct from chronological age; the years of age indicated by the condition and the utility of the structure". Effective Age may be greater or less than actual or chronological age. It is measured in economic terms as an indicator of diminished utility.
Economic Life: This is "the period over which improvements to real estate contribute to the value of the property".
Remaining Economic Life is Economic Life minus Effective Age.
All the references have one common theme--condition and effective age are almost synonymous. Condition determines effective age, effective age represents condition.
So now we know why the new forms have the words Actual Age in the grid. Condition and effective age are the same thing so one adjustment only. Actual age is a fact and there may or may not be a market reaction to the differences in actual ages that has nothing to do with condition.
A 1890 house that has new roof, new plumbing, new electrical wiring, restored woodwork and floors, etc, etc, etc is in very good condition and either a minus or plus adjustment would be necessary depending on the condition/remodeling/renovation/restoration of the comparables. It however remains an 1890 house with the floor plan, layout, bone structure, etc, etc, of the 1890s--therefore if one of your subjects is a fairly new house within the past ten to twenty years there would be an adjustment for the difference in the actual/chronological age based on market reaction to those differences that has nothing to do with condition.