Hi Keith,
I have a few T4x keyboards with gray bumpers in my collection. I guess you don't have the 3 black plastic scissor mechanisms in place? All you see are 3 squares with sharp metal catches, and the middle one has a grey bumper? (Only the middle one is supposed to have a grey bumper, that's how it was designed).
Hooking in and snapping on the Space bar key cap is easy, but correctly intertwining and hooking in place the 3 separate pieces of the black plastic scissor mechanism is a pain in the neck and will require some patience. If you only try to snap it in place without catching the plastic bottom and top edges correctly it won't flex up and down properly when you press the <Space bar>. And you have 3 separate scissor mechanisms to do. This kind of assembly work is best left for a little guy in a factory in China somewhere LOL.
Now having said that,
let me share a little trick I found through experimentation. This works on T4x keyboards with black bumpers and probably works on some other keyboard mechanisms:
Firstly, get a very tiny flat head screwdriver. It may prove handy. Make sure the sharp little metal catches on the keyboard are not bent or twisted. You may need to straighten and pull them up a little using the screwdriver. Remove another keycap on your keyboard for reference if you need to.
Secondly, make sure the 3-piece black scissor mechanisms is hooked together/intertwined to make a single tri-une unit (a Trinity so to speak). I would send them to you already hooked up.
Thirdly, hold the tri-une black scissor mechanism turned on the right side and orientation (remove the keycap from another key and use for reference as mentioned before). Now, lay the scissor mechanism about half way into the empty square space you see and gently but firmly/slowly slide it all the way up until it is hooked in on top. At the same time it will hook in on the bottom. If it's the middle square you are doing with the grey bumper there in your way you will have to keep pressing the scissor mechanism flat as you slide up. Don't let it lift up. A little tricky but you will get it. Be careful not to break the tiny plastic leg hooks at the top of the mechanism or the mechanism will be ruined.
Finally, this part is pretty easy: Make sure the thin metal hook is snapped into the bottom of the <Space Bar> keycap. Hook it around the 2 sharp metal catches on the outer edges on the keyboard. Pull it so it's tight and stands up at the bottom. Then drop it onto the 3 black scissor mechanisms nicely aligned, double snap with both thumbs and you're done
I have the keycap and several other little pieces you would need. If you wish to email me (see signature below), I will be glad to mail these out to you no charge...no big deal, just do a mitzvah (good deed) for someone else today.
Daniel,
the little YP in NYC.
" We had pizza in the Lion's Den
"