Short Version:
I bought a 300mm zoom lens claiming to be a K mount but it's actually a Nikon F mount. What would you do?
Long Version:
So... I played eBay roulette this week and purchased a lens labeled as "Sigma Zoom 100-300mm f4.5-6.7 DL for PENTAX K-Mount". There were no pictures of the mount itself listed, so I knew it was a risk, but the price was right.
Turns out it is a Nikon F mount. It has a tab that prevents it from being inserted into the camera, and I can tell from the end cap that the diameter of the mount is a little smaller than the K mount, and the lens is built to rotate the opposite direction of Pentax's in order to snap into place.
I have read on the forum of people shaving off the tabs to force the lens into place and using them even though they don't lock into place. (I would be hesitant to do that since this is a larger zoom, although it is much lighter than my other 300mm zoom). I also know that there are adapters for different camera mounts, so I could look into one of those. Return isn't an option, but I could resell to someone else I suppose. Everyone else I know who has a DSLR uses a Canon, so gifting a Nikon lens to a friend isn't an option.
I am not really bothered by it, as I said it was really cheap. I don't want to keep it if I am not going to use it. The lens itself seems to be in pristine condition; I believe most of its life has been spent in a lens box with a UV filter installed and both lens caps attached. I was very disappointed that it had the wrong mount.
I am just hoping to draw suggestions from those with greater experience.