Hey Nik! No need to give up!
Your vest is too tight, and if you can't let it out any, you may need a new one. Sorry bud.
If you can let it out, do so, and then you'll have to make new JP holes.That bottom cross bar buttonholes out just above the hem (my vest is packed away for the next couple months, so hopefully another kind soul will post a picture of theirs), and so long as the holes can't be seen,the top slits can't be too big!
In your first picture, it looks like the the back plate just needs to be hiked up. You're best bet Nik is to try and link up with another Fett-Head nearest you. Good luck!