If the box says 10750, then that should be right.
Usually my receivers don't scan in the exact frequency listed on Sathint, etc, either, it's usually a few MHz off.
If yours is only a few MHz off, it's probably OK, as long as the frequency isn't wandering with temp changes, powering on/off the receiver, etc. I've had a few here that have gone bad, they scan in fine when it's cool outside but then when the sun warmed them up, the channel would go out. Rescan and it would scan in at a different frequency and then at night, when they cooled down, same thing all over again.
If you do change it, I'd go with a PLL like Brian suggested, I get much better performance with the PLL's LNBF's than standard ones. I'm not using a Cal-Amp feedhorn like you are though, so I don't know what LNB would be good for that.