Yamaha Tenor Sax
Model YTS-2X1

Serial No. - 1002

Look close and you can see that the "T" in "YTS" has been double-struck.
Also, the "2" in the serial number was first struck sideways and then struck again right-side up.

That's right...maybe half of the tonehole chimneys of this Yamaha sax are soldered in while the rest are 'drawn', like a normal Yamaha sax.
I think that adds to the argument that this may have been a prototype sax.
Lets see...the following toneholes were soldered in:
- Low C#, Low C, Low D#, D, F, Side F#, G#, G, Side Bb, Side C....that's ten of them which are soldered in. Maybe a couple of others...hard to tell.
The low D (first 2 photos of the bottom line of pix below) and the low C (third and fourth photos) had come halfway unsoldered. The last (fifth) photo shows the low C after I resoldered it.

March 28, 2011 - I wrote off to Yamaha a week or two ago, inquiring about this horn and this is what they had to say:
"Thanks for the message! It sounds like you have a very unique instrument on your hands.
Unfortunately, this instrument is much older than any records we have on hand.
It may very well have been one of the first student saxophone models that Yamaha produced in the early 1970's.
I'm guessing that it may have been so because the "YTS-2X1" indicates the model number for this particular instrument may not have been decided yet - and many Yamaha serial numbers begin at the number 1001."