We need more info. A detail picture of what you have there would be ideal. It just "doesn't sound right" that Univair doesn't sell "just the fitting". Sure they do. Now, you MAY have something out of the ordinary that someone incorrectly put there, or you MAY have the streamlines tailbrace wires (which are prone to "nicking", and require an inspection frequency designed to irritate an Owner into replacing them with "new stuff"). If someone has not replaced the tailbrace wires with the round ones, AND if your fittings are the "folded over" type (as opposed to a "flat, angled lug",) then Univair does indeed service then as "piece/parts" (meaning, they DO sell "only the "spoke nipple" part, as a unit). If you have the "flat fitting" and/or the streamlined wire... you should indeed consider the [rather seemingly over-expensive] option of finally admitting defeat to the Airworthiness Directive and I recommend replacing the tailbrace wire ASSEMBLIES, in toto.
I'm away from my desk, but someone should be able to easily chime in with the proper Univair part number for the nipple.
