767/757 has 1, 5, 15, 20, 25, 30 - which roughly correspond to the number of degrees deflection on the 757 (and if memory serves the 767's "Flaps 30" is more like 40 degrees).

The blocking off of Flaps 40 you speak of is done with a bolt (I've looked at a few -200Adv cockpits before scrapping)...a few twists and if you need Flaps 40, you can get it. (You can also still select it with the alternate flaps system.) Landing with 25 seems to limit the capability of the airplane, although in the stacks of stuff I have, I have no ODM, so couldn't tell you for sure.