Re flares/flashes. IIRC the photo flashes were fired from a 6 cartridge dispenser in the roof aft of the galley, whilst flares (which burned for a bit longer) were fired from the 3 x 6 dispensers on the stbd. There was a rack alongside the dispensers which held (again IIRC) 124 flares and 18 flashes. The photo flashes were nasty little beasts with quite a recoil, and it was not uncommon to find the dispenser coming loose from its mounting in the roof, although I don't think any flashes were fired into the fuselage.