Even two different sheets from the same or original prints can vary. One I had one half the wing was 3/4 inch shorter and 1/4 inch smaller cord. I had to determine which one was correct then mark the other to match.
Original print I build on and use wax paper over the print to protect it from the glue.
When I cut out something from the copy and before I stick it to the wood I check it against the one on the original print. I make note if I have to cut inside, outside or right on the lines.
In all cases use the original as the master and adjust where you need to cut so the parts match the original print.
You still may have to make adjustments when you assemble the parts so test fit everything before gluing anything in place.
Watch you do not build two identical wing panels LOL you would not be the first or the last who have built two left or right hand wings.
Look, look again and trial fit and look again. Measure 3 times before you cut. Heck I know guys who have cut it three times and its still to short. LOL.
Above all else keep your sense of humor and be prepared to chuckle at yourself on occasion.