CE-125 Dominie ECM mods, based on the EC-117 conversion... as witnessed by a Black Knight member who knew 'Sir Cedric' (the Knight's name) personally.
Common to early or late fit:
Delete APU, you need the aft weight allowance to fit a chaff dispenser.
Fit chaff dispenser. :)
Large scale Sqdn marking, the tiny unit marking used by 412 in the transport role don't cut it.
Early Era (alongside CF-100 Clunks/CT-133 T-Birds):
One extra VHF antenna, one extra UHF antenna. These support the EW Officer's communication set as well as comm jamming.
One 'T' antenna upper, one lower. These support the fore-aft radar jamming. The T's are airframe colour except for the tips (silver) and the emitter window (clear).
Red/Black rudder stripes.
Paint should be the gloss white used in the Transport role, but worn (except Sqdn markings). The A/C are treated as tactical assets, not transport. Marks left on panels by dirty gloves are not uncommon.
One pax window (starboard/aft) partially obstructed by EW console. Cabin windows are not polished as they are in Transport Sqdns.
Late Era (alongside EF-101 Electric Jet/CT-133 or CE-133 T-Birds)
As for Early Era, except:
More advanced chaff dispenser fitted, smaller exterior chute.
Delete lower T antenna.
Fit lower EW system panier (canoe).
Paint could be as per Early Era, but Gloss Black was actively pursued. If white, wear patterns more advanced than Early Era. If black, paint should be well maintained and most dirt smudges cleaned off. Markings should be the red-pattern markings as per EF-101 101067.
One forward window at front of cabin, portside, blocked by crewseat of EWO. Two starboard windows, forward and opposite of crewseat, blocked by enlarged EW panel.
Main landing gear doors should be open if A/C is parked. Preflight/Postflight Inspections require wheelwell entrance, the Falcon was modified with a ground access switch in the nosegear bay. There's no reason to believe the same wouldn't have happened to the Dominie, but safer... Dominie doesn't snap the nosegear doors when you flick the switch!
Interesting tidbit, if the Dominie is supported by 412 Sqdn in heavy maintenance, then there is a good chance that a Dominie right out of maintenance would wear 412 Sqdn markings in place of 414. This was a regular occurence on EF-101 '067 (In that case it was 416 markings). Pristine, clean and polished would be the order of the day in that case.
Diorama suggestions:
Groundcrew fitting pods. 'Tactical Start', on deployment it wasn't uncommon for a single groundcrew member to act as the startcrew (instead of the normal 2 person). In that case leave the airstairs open and run a comm line from inside the cabin to the single startcrew member. Post start the crewman will throw the nosewheel chock aside and the board the A/C.
Loadout: Chaff tanks (early era only) or ALQ pods.
Plumbing the hardpoints is a waste, EW Dominie isn't going to need the range.
I wouldn't fit an AAR probe, overspray will damage the upper T forward emitter window.
Puking F-15 'Ego' driver on the ramp beside the plane. It wasn't uncommon to see big, tough fighter pilots get motion sickness when deprived of visual cues during a flight inside the cabin. Almost guaranteed if some sadist of a Tech-Crewman and the EWO have a sortie-long conversation about how bad an idea it was to qualf down draft beer and chili in the Club the previous night. Air quality was 'sometimes' an issue, when it got real bad some joker of a pilot would turn on the 'No Smoking' light.
Of course, that's the realistic conversion. In the WHIF-World pretty much anything is acceptable. :)