I've just uploaded an outline into your gallery, take a quick look. This is based upon a standard shield template but done to your measurements. Looking at yours in appears slightly different shape but I've found one that may be closer.
What a nightmare but in the end I did a rectacle and put the image in it, and it worked, never again I hate rush jobs its for a pub thats opening Wednesday but wanted it monday morning and the art work was a fiddle, hours of work but at least if anyone asked again it should prove straight forwared, many thanks for the time all of you have put in to help me.
the frame was slight smaller than I needed I made it bigger but when I went to layer it it was two and half of inches smaller. but unlayered it was the right size and having a long day I did the best I could. Any ideas how I made it smaller by flatten it.