Stating serial numbers helps in reconstructing the flow of events. I left Thiel in 1995 and am playing catch-up with changes of various sorts. Of particular interest is that crossover manufacture was taken to Asia (with considerable care) and some performance changes. Over these past few years here on this forum, I've been able to piece together a picture of what happened when with what performance consequences. Thiel's Chinese crossovers used components that were cloned from the long-term "western" components. The layouts also migrated from point to point on masonite to high-quality fiberglas. My bottom line is that I prefer, subjectively supported with inferences from measurements, the original made in Lexington boards. But the Chinese equivalents are quite good - with some exceptions: we've found Chinese crossovers with downright sloppy coils that were audibly inferior when directly compared to Thiel's AcoustaCoil / ERSE coils, which I consider best of form.
This sleuthing would not be necessary if the New Thiel owners had honored and kept the extensive body of records that we kept from day 1. On the bright side, our view of Thiel history is gradually coming into focus.