Fuel line flair
FWIW, here are some pics of Blue Point flare tools...
The TF5a from Snap-On's website:
And another TF5a from Ebay:
And the TF528D, which we PM'ed about (pic is also from Snap-On's site, but mine is identical):
Note all the wing nuts are full thickness, without the scallops in the wings like your broken tool has. I think someone either swapped the entire tool, or at least swapped the wingnuts for something inferior. I'd be asking the seller for my money back.
If you weren't on the opposite side of the country, I'd invite you over to use mine.
Also, the pic of the Ebay TF5a looks exactly like my KD Tool, except for the "Blue-Point" on the mandrel.