For the CombaTech end of things, it's simple: The MGP Laser Rifle is lacking a manufacturer keyword in its base WEAP form defining it as a CombaTech brand gun. The CombaTech Catalog perk works on that manufacturer keyword, so the Cathode auto-laser pistol and MGP Ballistic Rifle were already benefitting.
The UC Defense Manual is more complex: each magazine size expansion at each perk rank is specified for each Alliance Armaments brand gun. Thankfully, the Orion laser rifle and Breach shotgun match the base magazine sizes for the Dogfight laser SMG and Resonator laser sniper rifle, so copying and altering their Mod Magazine Size perk entries on each rank to point to the new guns was done as the fix.