His "sch"s came out as "ch" in most cases, but that was just a personal feature, maybe the result of over-correction at an earlier point.

It's a hypercorrection I've heard from other Rhinelanders and Palatinaters, however. Someone I knew on sci.lang told me he had a Rhenish colleague who once said "elektroschemiche Zwichenchischt", much to the delight of the other researchers.