With a horn like that and from the 80s, it is most likely Taiwan made. I have a cheap 4" (no horn but 4 mounting ears) I bought from Western Auto in '82 or '83 and it is Japan made. No COO markings but I recall noticing that on the box. Was already seeing cheap Taiwan tools beginning to replace cheap Jap tools and a few years later no more "cheap Jap", only "quality Japanese".I had a 4" on my bench up until the first of this year. I bought it at Northern Tool in the 80's. I had another 8" jaw one built exactly the same just bigger. For fun I cleaned & painted and sold on CL for $50.00 ...
