Firstly, while I understand you might not have a similar reverence for the machine spirits, I would rather you not use the term “knocking up”. Crafting new technology is delicate work and I will be breathing life to a new machine spirit. Speaking of the spirits in such a way is quite disrespectful. Though I forgive you.
Most imperial firearms disassemble down quite nicely, the devil will be in creating a special briefcase with hidden compartments and neutralising any signatures. I could create such a vessel quite happily. I could install an electromagnetic stummer to avoid metal detectors and a X-Ray repeating material to the outside of the hidden compartment to fool X-Ray machines. If you are disassembling the precious shotgun then I will have to teach you the disassembly and reassembly rites. They are spoken in Technica Linguis, you will find the language quite eloquent.
I will visit my fellow priests in the Adeptus Mechanicus and search through the database of patterns. If I can find some UV sights with ocular interfaces I will take the time to craft them. I would suggest however that you would be better off having your eye removed and replaced with an ocular implant. The implant could be interfaced into a sight on the gun and provide feedback directly into your brain. Consider this well, I judge the members of this team worthy of being married to glorious machine spirits, an honour bestowed on few. If you need any further convincing, look at the work that Medicus performed on Xantius, beautiful!
The grenades should be possible, I’ll have to look at the catalogue in the temple. They might require special crafting though. Creating a hidden compartment in the heel of the shoe is a triviality.
Glory to the Omnisiah