[Linked Image from thumbs2.imgbox.com] [Linked Image from thumbs2.imgbox.com]

Yeah, those stamps of coupled/interlaced KR, whatever, are prevalent on post WWI platforms and are tube maker's marks where they transformed Belgian roughed bored tubes to a final product.

Too, I have seen the Heart stamp prior but it was associated w/ Emil Eckoldt.


Serbus,

Raimey
rse