how to spot an early Koetsu

I just purchased an old turntable, on it is an old Koetsu rosewood cartridge.Now is it real or fake. If real how old can it be? Sound is great, all things point to a mark 1, the only thing that doesn't look right is the serial number. The number is etched on the top metal part of the cartridge where the screws go in,the number reads 911 75,thats it no japan either.So can anyone help me out here?
According to Hiram Toro, Managing Director of Koetsu USA;

"On the surface most buyers can't readily tell the difference between a genuine and a counterfeit Koetsu. In fact, only a qualified Koetsu technician can truly tell them apart."

This is an excerpt from a Letter to The Editor published in The Absolute Sound, June/July 2009, Page 10.
Well if the sound is great it must be authentic?
Its the counterfeit Koetsu's that are a problem not early original Koetsu's versus late originals. Since only a qualified Koetsu technician can tell the "Fakes" form "Originals" apart that makes it hard for us buyers out here on the Gon. Buy from dealers and people you can trust.
Counterfeit Koetsu's? Maybe Grey Market. There is a lot not understood here about what goes on by a distributor to "prevent" the Grey Market from hurting his business. I have purchased grey market koetsu's & compared them to the US version. No difference. Even serial #s match. In the same breath, the manufacturer gives the Grey Market life. The manufacturer has fixed costs, and needs to have enough income to cover these costs. This does not always include cutting production and controlling all points of distribution. Even some of the most limited production watch companies in the world have "sanctioned" grey market distribution where they deliver directly to the grey market retailers. They just deny it in person, but they can't survive without the extra business. It is how they maintain their balance sheets. I know this for a fact. And to explain it further, some people will only purchase when they get a deal. Hence the existence of Agon. This has much to do with the growth of the grey market.
Interesting post, Dgad.
Thank you, it makes sense.
A manufacturer has no influence on final sales price (here we have the Zyx dilemma). Let's say, Koetsu give out a model for 600$ and the final price will be 5000$, how much orders they will get?
When there is a way to get that one for 2000$, will they get more orders? Probably.
You see it from all distributors, how much you have to pay for a "overhauled" cartridge. More and more stopped that (Too much work) and they replaced it with an exchange cartridge.
Do you think, they give any money to customer? No, even the Dealer has it's markup on these...and he no work except to write a new address....
try getting in contact with Koetsu, or their U.S. importer or a authorized dealer. i just bought a used Lyra argo i and i called their U.S. importer gave them the serial # and they told me when and where it was bought new and sent me a stylus guard for free!
I too, was'nt aware there were any counterfeit Koetsu's. Do they exist and has anyone been unfortunate enough to buy one?
There was a similar serial number ( 92862 ) sold on ebay - item #5877293558 . It was said to date from 1991 . It seems to be quite a late serial number probably from a period just before koetsu ceased to operate as a commercial company for a while in the early 90's . Don't think it is a Sugano Senior serial number unfortunately . I have never seen an actual fake koetsu but there are some blacks painted to look like urushis out there . Ian.