i was going to post this in some general discussion thread, but damn it, i want the attention! this thing has been bugging me for 2 years, and i need some sort of keyboard sherlock to help me out with this one. i picked up this model m ssk 2 years ago at a random yard sale. i was kind of a noob at the time, so i had no idea what i had in my hands or believe me i would have asked them this question on the spot. all i knew is that when i started pressing keys that there was something special about it and i didn't give it a second thought until i started doing my own research into these keyboards. i had no idea about the slight difference my model m ssk had compared to others
the difference being this...

the standard label isn't on this thing. i had to pop the top and look under the hood to get the actual info, and as it turns out, it was an early 1987.
this makes me think that this could have been some internal ibm use keyboard, but that's just the wishful thinker in me. but i've always loved this about my keyboard, it's was just another way of romanticizing it.
now i want to ruin that magic. so give it to me straight doc. is this board special or not!?!?
update: it's a 1986 prototype and has a couple differences from the normal SSKs such as different case moulding (lack of speaker grill, fresh texturing on surfaces that are normally smooth, a few other nuances) socketed eeprom, and it still keeps the old galvanzied steel plate. the internal sticker's shop date is 5390, so it puts it's production past mid 1986.