No affiliation; this winder in Serbia has been making some pretty interesting-looking reproductions of some of the harder-to-find vintage mic transformers.
Reviews over on GroupDIY have been very, very positive, and he's been over there as well documenting some of his process repairing, rewinding, and reverse-engineering some of these rare transformers.
He's just repaired and reverse-engineered the old Rohde and Schwarz V2545, which was the transformer in some early C12s (including the two best-sounding C12s I've ever personally heard).
I hope he can get enough interest to bring that one into production. He's just recently added transformers for the C12A, the C414-EB and C414-EB-P48.
https://www.mobytransformers.com