Examining a table lamp I found the live conductor fractured & insulation erupting!
Replacing a lampholder, flex & threaded tube insulator is easy. Brass switched BC lamp holder w/red safety pin (will not turn on if a bulb is not present).
Adding a cord grip is not easy. This lamp (and many more) are custom glazed pottery, Troika style, just a hole in the side.
I notice the brass lamp holder has an "strain relief bar" where you loop back the insulated cores - like some ceiling rose fittings that do not use a slotted-disc around the cable sheath.
Does that meet the requirement of a cord grip, so I do not need one in the base?
Otherwise I will have to diamond drill the side and epoxy in one of those plastic nylon cord grips with a plastic side grub-screw.