Help with Marking on Older Bear Riser

[Black Hills Archer]

I recently acquired an older Bear Kodiak with a marking I've never seen on a Bear riser. From the Catalog CD I have, it appears to be a 1960. It reads as follows;

DE 455
64"
60#
F.

I've never seen the "F." on a Bear riser. Any help would be greatly appreciated.

John

[Danny Rowan]

Better to ask in the Collector's forum, might get a quicker answer.

[Black Hills Archer]

Thanks!