So I spoke to a gent who was a member of a team in the 1960s who were tasked with doing their best to locate all the hidden tunnels in the Island in order to make them safe.
The reason for this was that after the war, much of the German equipment (helmets, guns, gas masks etc) had merely been thrown in the tunnels and bunkers by the Islanders and then sealed up. Naturally when wind of this got out in later years, groups of local boys eagerly set about exploring for Nazi bounty. One long tunnel complex was a particular favourite, and the story goes that in the early 1960s a group of boys who were exploring it lit a fire in it on their way out. This in turn burnt all the oxygen, so that when the next group went in, it was a death-trap. Two poor boys lost their lives, and the government set about opening up the sealed bunkers, recovering the german equipment and thus attempting to make these tunnels less of a temptation for bounty-hunters. (By the way, did you know that a genuine Nazi helmet goes for £500 nowadays!)
So, that was the job of the guy I spoke to. When I asked him if he remembered coming down to my neck of the woods, he said that although there had been some constructions checked, he could not remember mine. Furthermore, he also said that had they found it, they would have removed the "tempting" guns. So it just goes to show that even the team tasked with finding all the bunkers in the 1960s seems to have missed some! Makes you wonder what else there might be out there.
When I described the tunnel construction to him, he said that from his experience, it sounded that there was a distinct possibility that the steel roof in mine was made from metal that had been destined for French railway tunnels. He said that the Germans were adept at re-cycling all sorts of material for their fortifications built as they spread out through Europe. I guess that makes sense now....
I also asked him about the presence of British Lee Enfield rifles? Interestingly, he said that by the time the Germans reached the atlantic, they were running low on weaponry, so thought nothing of seizing guns from surrendering territories and issuing them to their own troops. He said that it would therefore not be far fetched to conclude that some German soldiers in the Island had been issued with seized Lee Enfield guns and british ammo!