Nothing to indicate original barrel length. Best way to tell if it's been cut--and I'm guessing, with Rockdoc, that it's metric and probably original--is to measure the chokes. If there's a lot left, almost certainly not cut.
"Rectifie" simply means the chokes have been "adjusted". Decarbonized steel.
Pretty much standard St. Etienne proofs. On the bottom of each barrel, just in front of the flats, you should find a crown between palm branches. If that mark is repeated more than once on each barrel, it means a heavier proof.
