@leatherback have you looked at this image from Meriggioli’s book?
I guess the trouble, too, is that there are 5-10 other cultivars that could potentially be mistaken for ‘seigen’ which are not in this image.
The only guy that i know who truly has a lot of them is Danny Use. Otherwise, people from all over (many from Germany!) email me looking for ‘seigen’ — what i’m getting at is, it’s unlikely that you got one ‘by accident’. By your phrasing it doesn’t sound like it was sold to you as a ‘seigen’?