Thanks, Hannibal Lecter. Trying two standoffs was my first approach, but the generic ones I have use different threads. The TJ-07 requires M3 female and 6-32 male. As for length, I read elsewhere that they are 8mm, though judging by how much my generic ones are too short, the TJ-07 ones may be even longer than 8mm.

I didn't find anything suitable at the local hardware store, so I contacted Silverstone. They just replied and told me they'd send me a quote for the spares.