Photos would help a lot. If your pool has straps it more than likely is not a Doughboy, possible but unlikely. Is there not one strap in good enough shape to measure off of? Replacing the straps is not a problem but you do need to know the width between side supports.

How many side supports on each side? Are the side bottom rails straight or curved? Answers to these questions would be helpful.

Here to help when I get more info, Dennis