Mark,
As an update, I was in an Idaho Youth Ranch Donation store today and saw 3 racquet ball rackets for $2.50-$3.50. They all had the large teardrop shape and certainly looked like flyfishing nets with the addition of a different set of stringing. Sure gives one pause. Where did you get your net and did you or anyone else looking at replacement nets find one of the ghost nets with the measurement markings in the net? I did see a completed net with this setup, but couldn't find a replacement bag marked that way.
Thanks for posting this as it certainly gets one to thinking.