I have a nice Doric with a #7 screw in nib assembly. Unfortunately, the little slider is missing, so the nib isn't very stable. (It was just serviced by a well known repairman.) The tines aren't supported well enough to write consistently, despite the repairman's best efforts. (He didn't charge me, so no flames, please.) He recommended that I look for a Gold Seal screw in nib. Does anyone have one?