I am building a kit of M-113A2 of Academy. It is a kit rich of options, but there are very approximative painting instructions and references to the decals sheet.
The sheet itself includes three blue rectangles and numbers 1,2,3,4,5,0 to insert at own pleasure (?), some small orange rectangles with 1-I 1-7-I, A13, 1-14-15-I, HQ-6; small black inscriptions ‘the holy diver’ and ‘pegasus’.
There is no relation between these numbers and the optional parts as the cupola with or without armoured shields, or rear outer tanks, or the Dragon missile on the cupola, or the smoke dischargers or other options.
Besides the camouflage pattern of the instructions sheet (Nato, 3 colors) has a different pattern if compared to a photo shown on another recent thread.
Could anyone help me to make good use of the decals and options of this kit, please? Or suggest alternatives not including the use of aftermarket?
Thank you for any help.
Those blue rectangles and numbers are for ID purposes during REFORGER. Unless modeling a vehicle during that exercise (or any other) you can disregard.
As for the other markings such as the bumper codes, you’ll probably find you want to make your own once you’ve decided when/where you want your vehicle to be. Now comes the fun part - scrolling through scores of photos until you find the build you like, and then trying to replicate it.
Another note, if building a US Army M113A2, do not use the external fuel tanks. They were not used on US M113A2s with the exception of the M981A2 FISTV. The US started adding them on M113A3 versions. Other countries, such as Canada and Israel, did use the external fuel tanks on M113A2s.
For the decals, as Rob says, the colored square with numbers is an exercise marking to show which “team” the vehicle was part of.
The bumper numbers are both 1st Infantry Division. The first you listed is from 1-7 Infantry Bn, and the second one from 4-15 Infantry Bn. HQ 6 is the Battalion Commander’s vehicle.
The gunshields and Dragon launcher are all time and location dependent. Your best bet is to find a picture of an M113A2 you like and copy it.
That part is easy enough:
These are the official patterns from US Army Technical Bulletin 43-0209 of 31 October 1990, and they were meant to be followed quite strictly. Off the top of my head, the points indicated by measurements (which are in inches, of course 
) must be at those distances, with very little deviation allowed.