In reply to frqnt:
What Shearwater said.
I noticed this when I was remounting a new Speed Radical where there once were Plum.
2 of the toepiece holes should be OK (provided they haven't been stripped), so you would just need to decide whether to use the existing forward or aft pair of holes and drill drill a new pair accordingly.
I have a feeling on older Vertical bindings there was a fifth hole at the centre front of the toepiece, which has now been dispensed with completely.