Crosman Crosman 1701 dovetail / breech not level: issues mounting Williams rear site

Hi Folks, new kid on the block here. I recently purchased a Crosman silhouette 1701p and put the Williams notch site on the back. At first I thought I did it wrong, because there was a slight but noticeable tilt to it.

On closer inspection, It looks like the breech itself is slightly off center (rotated ever so slightly...) as it's mounted to the PCP tube, resulting in the dovetail surface not being level.

Is there a way to remedy this, and square up the breech? I don't mind rolling my sleeves up , and in fact I had to resist the temptation to just start taking it apart, but I've never disassembled an air pistol before. Has anyone else experienced this and have any advice on how to fix? Or should I just contact Crosman and see if they can make it right.