Thanks, Keith. I see it now. The second photo makes it clearer. That is a more sophisticated design compared to what one usually sees in the old crimpers, and the design accommodates different lengths of shells efficiently.
Miller, the BGI 1891 is definitely higher quality than most of the others I have from that era. The alloy or plating of the head would have been more expensive than the brass heads commonly used in some models. Good to see that there are at least three or four other folks here that find these tools fascinating and worthy of collecting. wink Gil