I have thought about a little bit. I'd like to help you out, but...
I have the perfect pattern on my Nine Ball. But I would have to strip the protector of my play field. I would need to trace it out on a fresh sheet of plastic. I make my cuts close and it is my opinion that no two play fields are the same so what fits mine might not fit yours without some extra trimming work on your part. And I am thinking you would probably have to trim it to fit anyway.
And the other thing is swarf. When using a Dremel Tool to grind away excess material it leaves fuzzies on the edges. There is no way I can get rid of the fuzzies 100%. So what happens as you lay the protector down and start playing all of these fuzzies start flaking off and get under the play field and after a fews plays you have to remove the protector and wipe all of the fuzzies off and then replace the protector.
I got a few games on with the new protector and already I see I will need to remove the protector and clean everything down again. I have swarf fuzzies already---and no matter how much you sweep, brush, air blow, no matter how much you clean beforehand there is always some small piece of crap that comes from who-knows-where and gets under the protector.
With the work that is involved, especially since I am guessing you will still need to do some trimming work, I would much rather see you spend you money on a few tools and supplies you would need then I could give you instructions on how to make your own. If you have an iPhone we could even do the teaching on Facetime. It would give you a better understanding and you would appreciate it more.
If you are slightly more than halfway handy with a screwdriver, I could teach you how to make one. I don't mind teaching and teaching comes for free. But if I cut one it would cost. And I have about 3 months work in front of me already.