I've seen references which suggest that NEMA 1-15 style was used in the past (that's the two-hole ungrounded version) in both France and Germany, but I've never been able to confirm that.
The only case where this is definitely true are isolation trnasformer shaver sockets, most of which would indeed accept both round 4mm pins and NEMA 1-15. I've also seen a few Italian made dou sockets of that type but standard ones w/o transformer. As far as an elderly radio guy told me Austria always had round pin ungreounded sockets for 110V AC and 220V DC and AC, but I'm not sure whether there ever was something like 110V single phase, more likely it was 127V delta.
