"and YES thats the U thats on the headjoint, does that mean it has an upgraded headjoint?"

That means it's Muramatsu alright. Also, you can check its model from under the lip-plate:
http://i927.photobucket.com/albums/ad112/pyrioni15/DSC05042.jpg
http://i927.photobucket.com/albums/ad112/pyrioni15/DSC05047.jpg
http://i927.photobucket.com/albums/ad112/pyrioni15/DSC05049.jpg
Can you see the GX printed under the lip-plate? also there are two number also printed under EX or GX, should be the last 2 digits of the serial number of the EX or GX(but I'm not very sure, I only heard from my friends).

<Added>

Inside my lip-plate it prints GX and 35:
http://i927.photobucket.com/albums/ad112/pyrioni15/GX.jpg

I just see.
E and on the other side ##
.
the flute also says, where the headjoint goes in, 6/521 or somethin like that...
does that mean they only made that many?

should be Muramatsu EX III, just buy the Mercedes.
it's a hand-made flute, they didn't mass produce.

awesomeness...thanks for all of your help

Hey, my EX never had anything engraved under the lip plate. Weird! I wonder why Muramatsu would put it on the headjoint as they are the same style/cut from the EX all the way up to the DS, unless you get the Tsubasa style.
Yes, by all means go for the Muramatsu!! That is a steal!! I love those flutes! I bought one to use as a backup to my Powell (when I had the Powell) and ended up using it more as my main flute because it was much more comfortable on my hands. I had to sell my EX in order to fund my new Miyazawa No use having two good flutes for me as one will just sit and I have student flutes handy all the time that I can use as backup.

By the way, since talking about brands... the new Avanti flutes are wonderful!!! I bought one to play test and trial for a while. I plan to sell it though, as like I said, I don't need two nice flutes like that. I got a good deal on it, so why not! I did do some speciality extra work to make it even nicer. But over all, it is super nice! So, if anyone is looking for one of these and wants to grab it before I list it, let me know. I don't plan to list it until next week or so.

I heard different story here, flute people here told me new EX and GX are engraved under lip plate, DS and SR don't have any engraving under lip plate.