Clues or clueless?

In the author's opinion old buildings with character should somehow "speak to us" about their past lives. 

Pargeting "the bondo of buildings" usually hides many imperfections.

The five upper windows are additions to the original structure. 

Massive weight-bearing hinge plates carried huge doors. The plates were as large as 18" in depth and 12" in width, embedded within the brick layers. Some stable walls were three bricks thick.

The original 100 year old wood frame peeks out from under the plaster. The marginally protective bars have trapped a screen that has probably not been used for the last 50 years. This "window" has been created in part of the space that was originally occupied by a stable door. The infill space is likely composed of an odd collection of various bricks or blocks - now hidden from view.

Clearly the flimsy nut and bolt in the right hinge plate served a less demanding function than the original pivot point hardware. 

Human-scale doors on the side almost always accompanied the large horse and carriage entrances. The "free-floating" lintel may have been the based of a hayloft door at one point, although the location is a little odd. 

So here's the question ...

How far should one go (or be compelled) to respectfully acknowledge a building's past lives when it is being adapted to yet another life?