Early in the 90's my shop had the Fremont Unified School District contract for servicing the Apple computers. We did hundreds of keyboard replacements! Apple was just up the street from my shop and Apple shipped us 10 of these and asked us to report back on the durability. Well these worked out very well. I was just clearing up the warehouse and I found this one Prototype left on the shelf!
The production keyboards have the product information cast into
the base of the keyboard, or they have the label relief cast in to the
base. This is one of the pre-production prototypes used to test prior
to production. NO part number no casting outline.
The production units were made in Malaysia , Taiwan, and Mexico. The production units have a casting relief for the part number and information sticker , the Mexico production units have the part number and information cast into the rear of the case. This prototype was produced in the Apple quick fab facility.
To the guy that asked me to open it up to see if there are signatures cast into the plastic... Put in a bid! I don't think this is a fab-prototype like my Mac case with the signatures inside. These were the first produced to test out, that's how I got these.