I've done the physical and electrical mods myself, actually exceeded his mods, and can say that they turn a cow's ear into a silk purse. It is well worth having him do your mods. He is extremely experienced and does a great job.
You'll end up with a really nice pair of mics that can stand up to any, "yes" any mics out there recording PA systems.
I recently used a pair of the for an ambient tracks on a multi-track Vignola/Pizzerelli show and they work fantastic. I had a pair of 84's, CCM4, SM69 sitting in a case and used these instead. They did a fantastic job.
I've also used them on OH and they work really well, too.