Hello All! Maybe I am late jumping in on this thread, but I had looked into Islander RV's, best I could, before I bought one last summer.
Not absolutely positive, but my understanding is Islander RV Industries started in Bishop Falls, NL (near Grand Falls-Windsor, NL - about 4 hours away from St John's). As others have mentioned, there was also the Islander RV Industries in Langley, BC. Both shops have long since been closed. I think the old Islander RV Industries shop in Bishop Falls is now "Newfoundland STYRO Inc".
I have attached a couple of pictures of my Islander RV boondocking here in Newfoundland this year.
For those interested in a 1997 promo video from Islander RV Industries in Bishop Falls, NL, you can check it out on YouTube: