Hi Ron,
Question #1
YES, the early Launches of Redstone missiles were ran by ABMA...That stands for Army Ballistic Missile Agency out of Redstone Arsenal Alabama, It was Run by General Medaris and Werner Von Braun was it's technical director.... They were all labeled ARMY in some fashion...
Question #2
NO, the old Revell model is the only game in town unfortunately... Originally it was built for Redstone launches at LC-4 but was moved to LC-5 shortly afterwards... It represents the first of the Three Gantries that were at LC-5/6 and LC-26 eventually becoming known as the LC-5 Gantry... After Gus Grissom's launch, it was folded and left sitting for a few years before it was scrapped... The Revell model only casually resembles the actual Gantry and yes it needs significant modifications to make it match the actual gantry even for the early years before Nasa altered it even more for Mercury Redstone...
Gunters Space Page has a listing of all the Redstone and redstone variation launches for both ABMA and NASA...
https://space.skyrocket.de/doc_lau_fam/redstone.htm
Hope it helps...
Elmer