Scope Bases Different Heights?

I bought a used Stevens 200 SA rifle and the guy included what he said were Leupold weaver-style bases. I tried to mount the Simmons package scope on it that came new on my Savage, but the crosshairs were so low the scope didn't have enough adjustment to bring them up to zero. I noticed that the rear base was higher than the front. I replaced the bases with the same height ones that came off my Savage package gun and it was fine.

Now the same guy asked if I'm still interested in buying the Leupold scope he had mounted on the Stevens. I am, but am concerned it could be slightly bent if he had it tightened down on the different height bases. He was using Leupold weaver-style rings but I assume they are same height front and rear?

The same height bases off my Savage package gun were like these...
http://i202.photobucket.com/albums/a...61AA5305F3.jpg

The different height (Leupold) bases look like these which say they fit a 10/110...
http://swfa.com/Leupold-QRW-PRW-2-Piece-Base-P968.aspx

Does anyone know why the Leupold bases would be different heights? Are the Leupold weaver-style rings different heights to match the bases?

If they were meant for a flat rear receiver the rear (flat ) one would be taller. It seems like it would be kinda obvious during mounting on a round receiver though.
OR are you trying to install round mounts onto a rifle with a flat rear? that would also make a difference.

The Stevens and my Savage both have round rears. The mounts with the higher rear were already installed on the Stevens when I got it.

Only thing I could think of is that either someone put a flat mount on the Stevens, or Leupold makes their rear weaver-style mounts higher and uses two different height ring heights.

Sounds like somebody was mixing and matching.
I have a parts box with a bunch of scope stuff in it.
It really pays to keep it all separated in ziplocs or original packaging. Once you start throwing in loose components you wind up with a bunch of loose mis matched screws,bases and rings in a hurry. It can be a pain to sort it out especially when dimensions imperceptible to the naked eye can make so much difference.