"1 foot dip in stripe on back of cab" - The bottom of the yellow stripe is located at approximately 3.5' feet above the walkways on the long hood. On the side of the cab, the stripe is at 3.5' feet above the bottom of the side sill, therefore there is a ~1 foot drop in the stripe that occurs on the backside of the cab. Note that the GP38-2's do not even have a stripe on the fireman's side back of the cab, likely due to the electrical box located there (South East didn't like messing with difficult striping evidently... see below). This is difficult to model, but I've had pretty good luck doing the following: Place the stripes on the long hood at the correct height, then place the stripes on the cab side at their correct height. After using your favorite setting solution (Solvaset© is fine for Coal Belt Decals, and LOTS OF IT !!!!), cut a small piece of striping about 2'-2.5' long and arrange it on the back of the cab. Some cutting of the ends of the stripes is necessary so that they are lined up right. This will take some figuring, trust me, but it will work.
"Stripe is broken over all louvers" - On all GP20's, the red and yellow stripe is missing over any and all louvers on the long hood section. The easiest way to accomplish this look is to place the decal on the model then cut it at the louver and drag it to the other side.
"Fire Extinguisher Inside" - Ok, you caught me on this one. I was supposed to have included this in the decals, however I never did make the graphics for it. There is a sign close to this one on the old Walther's diesel data set, and I think that there is one also similar enough offered by Microscale, though I do not know which set it is included in. Email me if you need assistance finding the correct decals.
"SECX GP38-2 ..... Heralds .... centered on "point" of ends" - After looking at these photographs for years, it still had to be pointed out to me (Thanks, Anthony !) that the GP38-2's stripes' have a dip in them at the end of the long hood, similar to the short hood. If you look closely at your Placement Diagram at the photo of #3822, you can see this dip in the stripe.
This set may be used for the Green Scheme as well. Omit the red and yellow stripes, as well as the cab-side stenciling and "Fire Extinguisher" sign. All other lettering is correct for this scheme as well. I do not currently have access to any photos of the Green Scheme, however there is one photograph of #2001 and 2002 on page 65 in The Louisville and Nashville in the Appalachians book by Ron Flannary. As shown in this photo, the cab and rear heralds are placed in the same locations, while the front herald on the GP20's is located near the top of the hood. The GP38-2's, however, still have the herald placed below the low headlight, and have white numberboards with black letters.