[matthufham]

1) hot glue!
2) you could trim the nuts
3) enlarge the holes
4) there's always zip ties, 1 or 2 zip ties can't hold it but if you do all 8 or so holders with zip ties it'll work.
5) nuts and bolts. that's my last resort because it's the most expensive way to go if you don't have that many matching nuts and bolts.