Okay some more pics. The grime is all of the crud that settles in the upper reaches of old buildings. As an electrician I've encountered various types of it while working in scores of old buildings. It can get pretty nasty and corrosive as it collects over the years.
The cranks are Durax with Simplex rings. Hubs are three piece Campy, locknuts stamped CAM 58. I don't think the barcons are the earliest ones as they aren't engraved 'Gran Sport'.