Just got home from the museum. Some answers to your questions but for me brought up more questions. Here is what I have found out.
The book I have which I have attached the drawing has the lights labeled Resin Lights. They are numbered 143 and 81 which are on the out side edge of the port and starboard aileron. Remember this drawing is labeled for a Mk II mosquito. I have seen line drawings for the resin light in them though for Mk IV.
144 and 83 are labeled port and starboard navigation lights.
I found no lights on the bottom of the fuselage on the mosquito at the EAA. Doesnt mean one did not exist. I dont see any in the drawing provided either.
The museum mosquito did have a white light about 3 to 4 inches in diameter mounted on both the port and starboard wing in between the engine and fuselage on both sides pointing straight down. What they are for I have no idea. They look like they would be pretty bright if turned on.
The resin lights look to be around about 1/2 inch in diameter tube with a glass or plastic lense running about a quarter of and inch wide down the centor. Have no clue what they would be used for. From the look of them they would be no good unless you where right behind the aircraft and it was very dark because they are so small. Because they end is cut straight down you probably would not see them on at all from the side. Maybe signal lights for lead aircraft to other aircraft if they wanted to maintain radio silence???
Two lights on very end of tail. Top one is tail navigation light. Bottom one is tail formation light. The museums tail only had the navigation light which was white. Book does not say what color tail formation light would be.
The serial number of the aircraft at the museum is RS 712 if that helps. There was no info on manufacture series of aircraft that it was.
F-EG is the identification marking on fuselage.
One interesting fact about this plane is that it is still fully flyable. Even has oil still dripping from the engine's
Hope this helps
Micdrow