Vintage Coinmaster ?

[jim-g]

I'd like to get some information on a "Coinmaster 4000/d Series 3". I bought it at a flea market last weekend. It seems to be in excellent condition although I haven't had a chance to thoroughly test it out, I do get a threshold tone and it reacts to the steel toe in my boot . The guy I bought it from said he only used it a few times and it has no problems. I see a lot written about other coinmasters on the net, but can't find much about this model. It came with the original owners manual and another manual (Introduction to G.E.B. Coinmasters by Jimmy Sierra) although the Jimmy Sierra manual doesn't mention the 4000/d series 3. Is this a decent detector? how does it compare to the other coinmasters of this vintage?
I detected for a while in the early Seventies with a Jetco PI, wow I dug a lot of pull tabs back then. In the Eighties I picked up another low end detector as I always seemed to be too broke to afford a decent one. Found some nice coins with it though. About five years ago I bought a Fisher 1280-X and really like it for the beach. Anyway, any info on the 4000/D would be appreciated. This is a really informative site.
Thanks
Jim