The ONLY way to know if it's an XP or MP is to look at the CPU. I have a DUAL XP1900 and on power up, they are identified as MP's, not XP's. I connected no bridges and made no mods.
If I OC the FSB, the chips may then get IDed as MP 2000, 2100, or 2200 (the highest I could POST at), depending on how much the FSB was running at. At 143 FSB, I get something unusual: it tells me the clock freq instead of the PC rating. I imagine this will happen at other settings too, but this is the only time I noticed it.
Apparently the BIOS figures out that at a given clock rate, the chip should be a particular PC rating, and 1714 doesn't correspond to anything it knows. Note that I didn't change the multiplier, because I can't do that with this board. I am sure the CPUs could go faster, and that my 762 NB is what's holding me back.
WCPUID won't tell you what CPU you have. At most it reports what BIOS tells it (in my experience) and the current clocks you're set at. Sandra does the same, so it won't tell you either.
I hate to sound like a nay-sayer to a newby, but if you don't know that much about putting computers together, you really don't want to go cracking the case open and learning by breaking stuff. Most modern heat sinks are a little tricky and a simple slip up can result in a destroyed motherboard or CPU. Even the experts screw it up occasionally. Rest assured that no one is going to accidentally give you something worth more than what you paid for, and that you have an XP.
If some one does post instructions for how to do this operation, they will hopefully also have some useful pictures and diagrams so that you know exactly what you're doing before you try to do it. And none of us are going to take any responsibility if you break your equipment. Any tech worth his salt will ask for help when he's dealing with something he doesn't fully understand or a task he isn't confident he can undertake.
I'm not saying all this to scare you away from learning how to do this stuff, I'm just saying that if you can get some one to come and show you what's going on when you don't know something, that that is a better idea than breaking something (unless you can easily afford to break it, then go right ahead!).