Thiel Owners

I actually found a guy who has some 2.7s and 3.7s available. I am interested in both, I’m just waiting on pricing and pictures. The 3.7s have a serial number in the 600’s. I have read, in this thread perhaps, that the early original production run of the 3.7s had a metal dome that was tweaked in later runs for a composite(i think) dome. I am assuming a serial number in the 600s would be a second or later production run, can anyone confirm this? And does anyone know if there are any pros and or cons, or problems, with either version of the dome? Thanks!

FWIIW:   mine are 129 and 130 so very early.   I would call Rob Gillum and get his info on this.  when you say dome are you meaning the tweeter or the actual cap on the top of the speaker

I meant the black cap on the top of the speaker.