I think I have one too. I have to check the numbers. I happen to have the book. It's listed as "The International Offshore System 3000." At least that's what it says on the cover of the Information Manual. If you want it along with the original owners manual let me know, and you decide what it's worth. I have never used it, it came with my present boat. I had it removed when I updated all the electronics, I assume it still functions. It is a rectangle shape with a digital read out and it has two knobs, one for FT-M-FM
the other is for a depth alarm. Seems simple enough to use.
Tony D