I tend not to remember what exactly angle the angled riffles were at, but I may have that data someplace. I do think the BGS device was about ten* from the stroke line. Also, Wilfley's desk was not rectangular. It was 19" within the con stop, and about fourteen" at https://gold-alliance-ira92467.wizzardsblog.com/36188813/details-fiction-and-user-testimonials-for-gold-retirement-accounts