Hey Kadoka66,
first of all, thank you for the purchase!
The reason why the header image gets distorted is because the header has been programmed to scale up its background to fit the width of the screen. There are two solutions to this:
1). Add some custom CSS:
#main #header-image { text-align: center; }
#main #header-image img { float: none; width: auto !important; }
2). Create a wider image based on the existing one (e.g. 2000px wide), simply inserting the existing image at the center of a blank canvas 2000×300.
Please let me know if the above helps you achieve the intended effect.
Sincerely,
Andrii / Satori Studio