The old Signatures were pretty good scopes. The brass erector tubes were used because brass is slicker than many other materials, allowing the erector lenses to cam back and forth easier. But it's also heavier than other materials commonly used for erector tubes, the reason the adjustment turrets were placed further forward--for more leverage to consistently move the erector tube. This often made the scope a bit of a PITA to mount, which is why the brass erector tube was eventually abandoned.
