One photo with model name, caliber, and S/n?

I’m doing a Rhineland arms .45acp Mauser conversion
Original S/n, new engraved model name since there was none, & my trust info?

Since it's an unusual model, I would send the picture and make sure it has the original manufacturer and serial number markings clear.  If you added a model designation and then listed that on the Form 1, then I would get that in the picture as well for sure.

Your personal/trust info, it's fine to include but it's not needed really.  Many people wouldn't have it done yet at the time of form submission, and the purpose of the picture is mainly to help the examiner confirm you have the correct make/model/serial on the form when it's an obscure example.

I always recommend folks send photos when the make or model is not listed.

IIRC the examiner had an issue with my Sten MkIII SBR because it wasn't a recognized manufacturer or model in their systems. They asked for photos of the markings and I just told them that it isn't a conversion and I will be making the receiver myself as a homemade firearm. They accepted that information and issued the approval.