Another interesting Look just surfaced on ebay. This one features an unusual paint scheme with triangular panels similar to what you see on the carbon Look/TVT KG86 framesets. Frame looks to be in decent shape, notwithstanding some touch-ups, particularly around seat cluster. All of the frame details match the details on my Look 753.



Look Early Production Bernard Hinault Reynolds 753 Road Frameset 57 cm Pearl | eBay

It is also interesting to read the seller's note:
"Built by Le Jeune in France for Look. There has been much speculation on the actual builder, but as the mechanic who orginally built this bike back in the 80's along with many others I can attest to the packing cartons had "LeJeune" on them. Well, at least the ones we sold did."

I have read a lot of speculation about who built these frames, from Lejeune, to Cyfac, Gitane, Hinault's personal mechanic, Rossin (very unlikely IMO), among others. If you trust this seller, this is at least one added data point for Lejeune.