Never saw this Golden Axe manual before

I bought a copy of Golden Axe in a U.S. "Sega Classics" case, and inside was a (European?) Mega Drive cartridge and a manual I've never seen before. It's solid black with no grid pattern on the front or back covers. It says "Genesis" on it, so it must be from North America, but I've owned every U.S. variation and I've never seen a manual with this cover. The manual is entirely in English and matches up word for word and page for page with a grid pattern manual I have, except this one has the "epilepsy" and "owners of projection TV's" warnings on the inner front cover, while the grid pattern manual is blank on the inner front cover.

http://i66.tinypic.com/2hfo321.jpg

Some games got released here with Euro carts and manuals. Quackshot and Mickey Mania come to mind but I am sure there's a few more. Many of the Euro releases were NTSC and not optimized at all for PAL. The manual is an odd duck for sure though.

1. Embed feature is your forum friend.
2. Pal manuals are horizontal.

Yes, it is a legitimate variant, and even though it has the Mega Drive cart and the unique manual, its not mismatched. I've had a few copies but don't know the origin or any story behind it.

Some MegaDrive games like a batch of Strider Returns came repurposed over to the states with a Genesis label over the MD one on the cart.

I've had mismatched MD carts inside US NTSC cases b4. Heck, they just packaged a PAL PS3 game at GameStop in my selection of an American case recently. These things happen all the time. Weird manual aside, I don't think these are mismatched from the factory.