Couple of things. First of all, the story I got about my rifle was that it was brought back to Denmark from a Sirius member. So there is that part as well in this.
Secondly, the rear sight. Thats the ones you say looks identical. The ones I have seen, look similar until you start to notice the details. There are differences. But as I said, I dont have an RGTC one here, so I can compare side by side. One of the main details is the crudeness of the machining done. Mine is rough to say the least. Sirius did not get ANY rifles with original rear sight. That was one of the requirements. It had to be changed. The 40 rifles was machined at Otterup (known now as Schultz and Larsen). This has been confirmed by 2 different sources.
Third. The front sight. You actually said it correctly. Mine is the original sight. Thats my point. The RGTC ones were indeed changed to roll pin sight.
As for the carving. My first thought when I saw it, was that it was also personalized by some hunter, because you are correct. If somebody did this to an army rifle, they were in trouble. I also think somebody did get in trouble for this. But the logo carved is not somebodies initials. Its the Home Guard logo. So I think it was between 53-60 by the guy who was handed the rifle from the Home Guard. I also think the carving is why it was handed to Sirius.
As for the ammo pouch. You would be correct that the normal army and Home Guard didnt screw it on. However, this is a unique detail from Sirius. They did. Thats why the fact that the ammo pouch is screwed on is such a big deal.
Also about the ammo pouch itself. This pouch is a Home Guard pouch. RGTC never got ANY spare parts from the Home Guard. Only Sirius got that. Thats the why the fact that mine has a Home Guard pouch means that it can ONLY be a Sirius rifle.
Last but not least. There is a difference is SAYING they have a Sirius rifle, and proving it. So just because you see pictures from somebody saying they have a Sirius rifle, doesnt make it true. When I started the research, I dug into this with the assumption that it was a RGTC rifle.
Oh I almost forgot to ask. If you own a RGTC rifle with the rear sight milled down. Have you ever tried attaching a scope to it?