Omega Seamaster Chronograph 2598.80

I purchased this watch a few weeks ago. It is a Omega Seamaster Chronograph 2598.80.

It appears to be in immaculate condition, right down to the red dot on the edge of the case back.

The watch has a serial which is 4860xxxx and the chronometer papers which came with this watch have a matching serial.

However when I attempt to determine the exact age of this watch using the myriad of omega serial check sites, all of them point to 1985, which is impossible as production only started on these in 1993.

Does anyone know what year my watch is from?

It only cost $1400USD, so I got a good deal on this one for sure!

Thanks

Well this and my blue version both came back from Omega. I only managed to take a few photos of this 2598.80 as I had to return it to omega. When I ran the chronograph the watch would stop running, even the chrono. I would stop and start the chrono and the seconds hand would start moving again. I thought that was pretty bad and then I also noticed the watch was losing A LOT of time, as in a few minutes per day and this is post service. I returned the watch and well I havent heard anything for over a month now other than someone from Omega over the phone say it had some issues. Oh well, I will take some pics when it is back, again.

I have this same watch with a serial number of 486..... and it comes back as a 1985 manufacture date also. Too bad there are no reliable serial number charts for Omega watches.