Input jack - Cliff / G-K / Egnater content

I am repairing an input jack for a guitar-friend's Egnater amp head. All I need really is the nut, which is a male thread insert for a Cliff type six pin jack.
So he ordered a part from amprepairparts, and it came fitted with coarse threads as opposed to fine as the Eg has, so that won't work.
I looked at my G-K MB200 head and borrowed the jack nut from it, which is fine thread and fits perfectly. If I can't find a clue as to exact replacement parts (Egnater was no help, not sure about GK yet), I will probably try another parts house, but that will be another blind try. Allparts has a Cliff jack that looks from the outside more like the jack in the Eg, so that may be a clue, but there's no way to tell if it's fine or coarse thread. For $5 I'll probably have to try it.
Anyone have a source suggestion for this, or a supplier that might actually know what they have?