I'd be really interested in seeing this. It's the first I've heard of direct testicular suppression. Is it just mesterolone, or androgens in general? Given the high natural levels of intratesticular testosterone it's a little hard to envision how a small amount of an exogenous androgen would cause problems. Oral availability of mesterolone is 3% or so, meaning you're only getting 0.75 mg from a 25 mg tablet. On the other hand, my typical dose-response relationship would make this like adding 40 ng/dL to serum DHT, assuming they act similarly. So it's not totally trivial.
I'll have a look and get back to (i have far too many bookmarks saved on my phone, i'll find it though)