Nony,
Seeing how the Bobcat fastners are all metric, you may have 35mm blind nuts in your plane.
Try the 35mm before going to standard Dubro hardware.
You may have to re-tap the blind nuts thread before using standard screws.
If you force feed the standard screw, you may risk the chance of locking/loosening/dislodging
the blind nuts in the stab, thereby creating some extra work.
Keith