The only downside to the unicomp keyboards is that the main metal plate inside with the contacts inside is assembled by melting the heads of dozens of plastic "rivets", forming a permanent seal that would need to be ground-off, then be very difficult, or impossible to re-attach. Would be far better if they just screwed it together.
You can replace plastic rivets with nuts and bolts: http://imgur.com/a/QroSL
Also have you tried to wash the keyboard? (disassembled as much as you can or atleast removing keys and springs first). You can put it thru dishwasher, just remember dry it throughly before plugging back in. (putting key sockets facing a fan for a day or maybe using hair dryer). I've washed one model M in a shower and let it dry on the balcony for a week and it works well.