Ok, so the owner/breeder has the fish in the picture, plus one or several more of them? And he's offering your friend offspring?
I can honestly say it's not strange that he's unsure - to be sure about L236 is not really easy ;) And how certain is it that the fish in the picture comes from Iriri? I was recently informed that L236 is probably not from that area after all, but from Belo Monte/Porto De Moz (further down the river Xingu)...But then again, the fish in the picture above could of course be from Iriri and then be something else than L236

It's very beautiful nonetheless. Perhaps you can ask for some more pictures of both parents and fry? If the parents look almost identical/were caught at the same spot/imported together (hard details to prove, perhaps) I think you should get some of them even if they aren't L236, because this species is still wonderful
-Haakon