How can I recognize Taylorcraft BCS-12D-4-85?
That airplane is registered as a 1946 BC12-D per the FAA's N number lookup service.  This indicates that it came from the factory as a BC12-D but then may have been converted later.  Conversions don't change the subtype.

As far as recognizing specific subtypes of old airplanes, good luck!  Many old, popular planes have undergone all kinds of conversions.  Bonanzas built as early as the 1940s can be converted to look like a late model V35B from 1981!  There are even mods to remove the V tail and replace it with a "normal" tail.  My point is that determining subtype from appearances alone may be impossible.

Link below...

https://registry.faa.gov/aircraftinquiry/NNum_Results.aspx?NNumbertxt=N43459