"Gently cleaned with anticipation of a full restoration." I'd prefer no cleaning but I guess that is okay.
I have seen a number of 3278 boards where the number row keys have front faced sub-legends that are just silk screened on and the person doing the "restoration" to make it look good for ebay wipes off half of them before going 'doh!'
This keyboard doesn't have those legends to remove but like most vintage items it is usually better if the finder leaves the dirt on and doesn't attempt to "improve" the item.
I have even received alps boards from ebay where a multiple keycap stems are broken off in the switch slider and they just glued the caps back on. Last time the glue wasn't even fully dry and the key wobbled off immediately.