TRY THIS
The back straps are from the ribs to the sirloin.
2 nice long pieces of tender meat
As soon as you skin it you can cut them out.Right
Now what we call...(dosent mean its right[])the tenderloin would be inside the body cavity(oppositt the loin half backstraps)on both sides of the backbone,right about where the loin is showing on the picture.
As soon as you drop thebelly out of the dear you see 2 red juicy pieces of meat next to the backbone.