The bolts don't actually hold the adapter on — that's what the o-ring does and the central spring steady does — they are there to limit how far the flexible mounts can rock. You could leave them the way it is without any real concern. Or you could use a standard bolt with loctite and just install it so the bolt head is at the same distance as the proper bolt.
As for getting a set, somebody here must have some spares who is closer to you that myself, here on the west coast of Canada but push comes to shove I'm sure I can dig up a couple.
Yours
Vern