Yeah, Heritage don't call any linen backed posters flawless as I recall, they can only be a grade or two down from the top condition. Linenbacked posters once backed will always need to have a backing glued to it, it will never be again in original (flawless) condition as supplied to the cinema. I also view fold line touch ups as potentially damaging to the poster depending on how it was done. Often posters are bleached when linenbacked which to some degree fades the printing. It can look better after bleaching but that is only because the bleaching has more noticeable impact on the white areas and the new relative between white and colours can look better, but overall it is faded somewhat.
My linenbacker told me to never linenback unless you really have to (you wont recover your linen backing money, it is no longer original as issued (+ may lose money), takes up more room, costs more to send by post).
Flawless might be to a collector who does not care for its history and just wants something that looks good to his/her untrained eye.
