Gunsmith Unstuck isn't really unstucking. Even when having the 12.12 builds straight from the wiki
Builds from base EFT won't work in a mod that overhauls how attachments work and weapon/attachment stats. You're either missing a requirement or have another mod that changes quests. I've checked GS nearly 10 times now and every time it's been the user getting the requirements wrong or using another mod that changes quests, there's nothing more I can do. If you can't get it working then I recommend using Profile Editor to complete them.