FRP Handsaver Q?

I have a new Taper Pro Im trying to mount FRP handsavers to, and would like to know how the bolts fit into the bar.

There are 2 countersunk long bolts with either black hose or clear hose and shoulder/no shoulder nuts.

Not quite clear to me.

Also does anyone know where to get some replacement bolts for the brake and clutch levers (shorter)?

Thanks much