is it 1/4 inch too tall? the 1280x768 screens are physically smaller than the 1280x800 and 1440x900 screens (14.0" vs 14.1"), but since you have a 1280x800 screen that shouldn't be a problem...
i'm not sure if 1280x768 is just for the z60t, but the three i've had all have that resolution and they are all smaller than the Z61t screen.
your bezel should look like this: http://www.ebay.com/itm/IBM-Lenovo-Z61t ... 1330wt_952
this one will only fit 14.0" screens: http://www.ebay.com/itm/IBM-LENOVO-THIN ... _801wt_952
and you can see the top area is slightly larger on the one that goes with the 14.0" screens.
these are assumptions but i'm 99% sure. i wanted to try something similar but realized the screens were physically different sizes.
the samsung screen you have is the correct one, it matches mine. so i'd assume the LG is good too, and that it's just the bezel sizes that are the problem.