Sadly I don't have the equipment or expertise to do it.
I have made contact with an engineer who also makes rifle components who has access to a high end sound pressure meter or whaddevayoucallit. He's the guy I will go to when I start my second batch of testing.
I have here 10 new suppressors which I will be doing sound and accuracy tests on. I am just waiting for a set of thread adapters to arrive from the US so I can test these (they are mixed threads, some are 1/2" x 20 tpi and others are 1/2" x 28 tpi).
When I test those I will add this abused one as a number 11, since I have a new A-TEC SMM4(6) as a reference.
I also have my beady little eyes on a 12g suppressor. A-TEC are releasing the A12 soon