Help identifying an old raft
I just received this boat from my dad and was hoping to get some help identifying it so we can make repairs. He seems to think it's a very old NRS Otter (70s maybe?), but when I reached out to NRS, they didn't think it was one of theirs.
Unfortunately, there is no serial number on the boat anymore, but we aren't even sure there ever was one (my dad thinks it's possible the boat pre-dates those requirements, but I'm not sure). I can't find any manufacturer, logo, identifying information, anywhere on the boat. He isn't even sure what material it is made out of, and all he was able to tell me was that "last time we patched it, we ordered glue from NRS."
While it would be great to know what the boat is, we ultimately need to patch it and get replacement valve covers. I've included close ups of the vavles as well. Sorry that's not a lot to go from, but any help would be much appreciated.