Hi Bill,
We both could be suffering from classic car research fatigue in our search for the highest quality reproduction parts and finishes LOL. SMS, SEM, ACC Inc. etc. all these initialisms. My brain is fuzzy.
I too recently received samples from SMS Auto Fabrics but I can't compare my original Comfortweave (now USD189/yard) with their sample as my car is stored thousands of kilometres away. Are you able to show/explain what you consider the variation/s? Could it be accounted for by age wear and tear (e.g. fading, stretching)? My seats have some damage and I have the decision to make, repair or have completely new seat upholstery made.
I've found SMS hard to deal with. One requests very specific information. They didn't answer my question, how much fabric do I need? How did they perform time wise with the delivery of your ordinary vinyl and how did they pack it, was it adequate?
I did find this about TMI's piping
https://store.cobranda.com/upholstery.html - extruded piping rather than wrapped. Maybe you could obtain a sample and see how it compares.
Cheers
Noel