We've been deep-cleaning every window and their frames in this house. Ken calculated that the individual panes of glass total about 220. (Because of course his OCD brain did that.)
Considering the condition of the hinges and other mechanisms and the debris we're finding jammed against the edges, we figure these haven't been tended to AT ALL in at least 20 years.
We've found a mummified mousse behind a hinge. We've found a mummified bird below a bottom sill. We've found tiddlywinks. We've removed enough dirt to start another garden. We've had glazing fall off into our hands. We've seen enough stuff that shouldn't be in a window frame to permanently change our souls.