Like forum member Rex Desilets who coined the wonderful term "diseasels" (a tip of the hat to you, sir! 
), I have decided to co-opt the term "forensic archeology" as it applies to model railroading.
My definition:
Forensic archeology is the research-based process used to discover the use and creation of a historical artifact appearing on a model railroad. It is most often employed when no written plans of the artifact survive.
The legitimate definition of term is as follows:
"Forensic archaeology can be defined as the application of archaeological methods and theories in a criminal framework; integrating those methods and theories (and paradigms such as 'context' ( Connor and Scott 2001: 5)) with those of forensic science and criminalistics." This is from
The Oxford Handbook of the Archaeology of the Contemporary World
We now return you to your model railroading. Carry on! 
George
