Since the poster has backing layers, one can
attach hinging materials to the linen, without
touching the poster. Strips of Japanese tissue
can be pasted to the edges of the lined poster
and those can be used to secure it to a backing
panel. Such a panel can be a combination of archival corrugated board and conservation quality
board, on the outside. The size you need will mean that the panel a number of sheets of these
materials and the expense will be high. The hinges
can be pulled to the back side of the panel and
attached with linen tape, there. The product will
be of preservation quality, but framing it will
be a greater challenge and extremely expensive.
Hugh