For the Channel Map:
Floating Luftwaffe Airman -
Luftwaffe Airman in Inflatable Raft -
Floating RAF Airman
RAF Airman in Inflatable Raft
Floating USAAF Airman in Winter Dress
USAAF Airman in Winter Dress in Inflatable Raft
Large USAAF Inflatable Raft with multiple downed aircrew
"Ski-shaped" V-1 preparation bunkers
Concrete V-1 launch ramp
https://upload.wikimedia.org/wikiped...l_Ski_Site.jpg
Walled Norman farmhouse complex - this would save a lot of time populating the map and would make the Normandy sections look a lot better.
https://encrypted-tbn2.gstatic.com/i...7U5A5jB-gLUbug
(also see the farmhouse in the background in the illustration of the V-1 site)
French site with pictures of preserved V-1 launch site at Douval Val Ygot:
http://www.jean-maridor.org/francais/ardouval.htm
Norman "Bocage" Hedgerow - basically, big earth embankments with trees on top. These provided serious cover for the German defenders and made attempts to land (or crash land) in Norman fields quite tricky, even ignoring all the other anti-landing devices.
https://theoldtopographer.files.word...file.gif?w=584
Norman Bocage Hedgerow with breach caused by "Rhino" tank fitted with Cullin device:
https://upload.wikimedia.org/wikiped...inhedgerow.png
"Rommel's Asparagus" - poles set into the ground with wires stretched between them as anti-glider measures and poles driven into the invasion beaches at an angle and topped with anti-vehicle mines. Extremely common defenses in Normandy in 1944. For simplicity, these could be made as "patches" of poles which could be placed quickly.
https://en.wikipedia.org/wiki/Rommel%27s_asparagus
Thames Estuary AAA Forts - These were serious deterrents to late-war German raiders attacking London or shipping in the estuary.
http://www.bobleroi.co.uk/ScrapBook/...GreatNore.html
Luftwaffe Rescue Buoy - These were deployed along the French coast during and after the Battle of Britain. They were commonly used by downed airmen on both sides, and were checked on a regular basis by both British MTB and German E-boots.
https://en.wikipedia.org/wiki/Rescue_buoy_(Luftwaffe)
RAF ASR-4 Rescue Buoy - These were converted launches which were moored along the coast along typical flight paths of Allied aircraft. They were first deployed in 1941-42.
http://www.undiscoveredscotland.co.u...ages/asr10.jpg
http://www.scubadolphins.org.uk/imag...Write%20Up.pdf
Various lightships, beacons and buoys. There were many of these during WW2, and they were used as navigation aids by both sides - at least during the day. At night, they were either blacked out, or just had low intensity direction lights visible. Lighthouses were also used as observation posts.
http://www.shippingwondersoftheworld.com/part4.html
Railway Marshaling Yard Objects, such as Round Houses, Engine Repair Sheds, Yard Towers, and Railroad Spurs. French Marshaling Yards were sites of some of the most intense bombing attacks of the war in the months prior to D-Day. Likewise, Allied aircraft devastated Italy's marshaling yards. On any front, they were natural targets for tactical bombers and fighter bombers.
http://www.translationdirectory.com/...o_Illinois.jpg
Bomb storage bunkers
Every airfield in the UK would have had one or more bunkers for storing bombs and other ordinance. The Luftwaffe had similar facilities but I haven't yet been able to find pictures.
http://www.skydock.co.uk/facilities/...e-/index.phtml