Having recently read Gunther's book DB Cooper:What Really Happened, and perusing all these other suspects that do not fit, the new information about the tie, fits well with LeClair, as he is, by far, in my opinion, the most likely of the known suspects.
The book was ridiculed when it first came out, and was dismissed... but evidence that came out well after publication, does point, and fits, as LeClair being Cooper. I am utterly amazed how everyone is looking the other way from this guy.
Everything, especially of the behavior of LeClair and especially Clara... the psycology and motivation are all very reasonable, and logical.
Gunther deliberately changed details as to protect the two sources, as he agreed....
Assuming it is LeClair.... to find him, one should contact Gunther's heirs to see if they have the original data provided by LeClair and Clara.....and then do a search based on that.... If its not available, then one should start with searching the Paratrooper records, and isolating all those Canadian born (gunther said London, Ontario which likely means its not there but in eastern Canada)... for this seems one of things that Gunther didn't shield... and then isolate the ones who went to a public university in on the east coast on the GI Bill (Gunther said it was Rutgers, so I figure it'd be on the east coast, but definitely not Rutgers for having said it). Then, of the few on the list, find the one who disappeared from his family.... those seem to me, the data points that Gunther didn't obfuscate.