Thanks for the detail, this is very neat. I wonder if transformers like this are in an "uncanny valley" of manufacturing where there is barely not enough demand to bootstrap mass production like for example turbines. Turbines have very exact tolerances as well, but it seems that with higher unit counts orgs like GE managed to churn them out.

Perhaps the liquid piece is also making things more difficult; I'm sure a dry object is a lot easier to warehouse until needed.