Differences in the TX200 MK's

So I recently ordered a refurbished Air Arms TX200 HC from Pyramid Air but when it arrived yesterday I was surprised to see that what I actually received was a standard TX200. I didn't bother calling Pyramid Air about it because what I really wanted was a refurbished TX200 MKIII anyway. My question is if there's a place I can find what the differences are that were that Air Arms changed from one mark to the next? The reason why I ask is because everyone that I've seen has the Air Arms logo carved on the bottom of the grip and mine doesn't. I also have one other question. Are all the TX200's sold here in the US the higher power FAC models. The label on the rifle bag I received says 'AA TX200 HC FAC'. Thanks in advance for any insight into my questions:)
 
The last Mark change was 20 years ago, so you have a MarkIII without doubt. The MarkIII came in around 1999 and remained the same until about 2006 when the stock checkering changed to the fishscale type and the safety button was lengthened to show a small red tip out the right side, when not engaged. A couple of years after this the bluing got even more brilliant. Other than that there has been very little change to the TX. I would assume a 12 ft. lb. TX would be special order for the U.S. market, so most will be FAC. An e-mail with serial# sent to Air Arms will give you a build date.
 
One reason why it could be refurbished is because they cleaned rust from the bore. The shipments of TX200's the past year or so have had rust in the bore to varying degrees. In many cases, it's hard to see without careful inspection. If you look in your bore with a magnifying glass you may see remnants of the rust, especially at the corners of the grooves/lands where it's harder for a brush to reach. Hopefully, they got it all and you see nothing, and you got a clean rifle at a sweet price. If there is a tiny bit of rust remaining, you should be able to keep the bore lubricated with Ballistol to keep the rust from expanding. 
 
TX 200 MK I - No shroud, no bear trap

MK II - No shroud, bear trap

MK III - Shroud, and bear
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trap