Bottom line is neither of you are going to agree on anything. Now my opinion may not be the popular answer here but here it is:
Naylor--- bring the motor back and dyno it at your shop. It makes the 1050 then send him on this way. If it is the 950 he claims, you can fix the issues.
Billy- hate to say it but you seem to be the customer most shops are glad to see leave. You have high expectations on limited budget with that have it now attitude. Nothing wrong with cutting cost but your results are what your budget was. Seeing your reactions and postings, I can see the attitude that Naylor mentioned getting when on the phone with you.
My verdict, no one was scammed. Simply just 2 people that can't do business together, period. It happens. One isn't going to be pleased and the other is done trying. It's a dead issue. Walk away and let it be done.