Maybe I did not phrase my response in an easy way to understand. Special naval landing forces are just a small part of the IJN's ground organization, in the Pacific War they deployed a little over 20 units, of which most saw action in 1942 before being disbanded shortly afterwards. In contrast, the IJN had at least 400 base forces, guard, air defense, construction units, etc in the Pacific. These accounted for far more of the IJN's ground presence, and while not serving purely as infantry, all these units maintained some form of armed component. Allied intelligence was well aware of this, but as time goes on history is forgotten and collectors have grown to worship the SNLF while more or less forgetting the others. Now all of these armed personnel on the ground more or less had the same equipment, which was a mix of regular naval items and a few naval ground-specific items, leaning increasingly towards the former as the war progressed. Items like lace up boots, khaki puttees and khaki wool field caps are a few examples of items intended for naval ground use. Canteens, breadbags, cotton caps, etc are just navy, but could be issued to ground troops too. Long story short, there's not any items the IJN actually referred to as "special naval landing force" items, at best it might be classified as ground use. This particular canteen being used by SNLF is another story, but the possibility of that is minute, especially given how little the SNLF accounted for the IJN's ground forces let alone the entire IJN.