Oh well, we tried.
It looks like you are at an impasse.
Either be in open, change the barrel, which could cost a bunch, or buy another gun - even more money.
Hock a kid?
There might be a way to tap the holes for screws, but if it isn't done exactly right, there could be nasty results.
And the folks at the match might not accept it for possible safety reasons, even then.
Have you checked into changing the barrel to see if it's affordable?
They usually don't just screw in and fit right.
Of course, if the barrel is long enough, it could be shortened past the holes.
But then the front sight would have to be dealt with.
It might be easier than a barrel replacement.