Ever build an archtop and forget to glue a reinforcing block on the bass side of the upper bout for a strap button before you closed the box?
Here is a way to save face.
Drill the hole for your screw in the right spot and thread a long sliver of spruce through it, bring it out the F hole, and attach your drilled block with a bit of CA and accelerator.
Pull it back in and you have good rotational control to position. When all looks good you can glue it and hold it in position with a spring clamp on the spruce holder.
A wire and tuning machine clamp as you would use for a crack repair could work but rotational control is a problem and you really need that here.
