It looks like with all your experience and skill you are able to cope with the inadequate instructions. So far, it looks like your usual clean, precise craftsmanship.
With regard to Rick's question about whether your tank is in U.S. Army or USMC markings, I am pretty sure that the Marines only used the M1A1 version of the Abrams, which (according to this
Stars & Stripes article) they have now divested themselves of
A farewell to armor: Marine Corps shuts down tank units, hauls away M1A1s - Marine Corps - Stripes
Don