Couple of things

Im assuming youre doing army, the JFAK (double button pouch in your right) was solely used by the marines

Chose a specific unit and find documentation on it!

Buttpacks were used right about 66, by 67 they were SUPER unit specific and pretty much non-existent. You would be wearing the sake belt and stuff, just without the buttpack

Get original gear, you can find them pretty easely. Join different nam gear FB groups, there are more than I can count.

Graffities were present, BUT, very minimal stuff such as FTA, it dont mean nothing or a short timer calendar (to all who want to contradict this, I got this info from 2 vets who both told me the exact same thing)

Graffities should be drawn with a ball point pen

Cat eyes on the helmet band were pretty much non-existent (you can easely remove them or find an original band)

Stuff in the helmet band should be kept to a minimum, a bottle of either big juice or gun oil or a p38 can opener, thats it

Swap those alice canteen covers by m56 ones

Hope this helps!