Also in the camp of not throwing anything away. Always save your stuff!
Anyway, a space bar from ALMOST any 7u Alps board SHOULD work. I've used a Focus FK-2001 space bar with no issue, but you will have to snip one of the two stabilizer pegs used on those bars. Snip the right one as the AT101 and SGI Granite use only a peg on the left. The original Alps-made bars had detachable pegs, but it doesn't matter much.
Some keyboards come with Cherry-like cruciform stabilization. That will not work, obviously. Most 7u Alps boards should be fine.
I can guarantee that an Acer 6011, and Focus FK-2001 space bar will work. I'd go for the FK2001 as it's pretty cheap and easy to find.
The only other Alps made 7u space bars with the detachable pegs are far and few between, and they all tend to go with relatively expensive boards.
Also, if you do not have the wire for stabilization, you can bend it yourself. I forget the diameter needed though.

It's very similar to the size of a #1 sized paper clip.