Here's a new version of an existing pak64 building (png attached):
(http://dl.dropbox.com/u/61716/resimprovement.png)
The new version is scaled from the equivalent in pak128 and tidied up in GIMP.
(edit: see post below for new version)
Honestly it looks more like blurred and creates a halo with the grating on the roof.
There were a few stray pixels (which I've fixed below), but otherwise my impression of the original building is that the thing on the roof is meant to be a kind of fence with holes in it (hence "halo").
I guess small differences like these are mainly a matter of taste anyway.