I collect a little bit of lots of things.
One thing about collecting vintage posters is that restorations performed properly (ie with water based reversible materials, with true to the original (waterbased) touch ups, linenbacking [not drymounting]) is considered a positive and value added endeavor.
I know that with sports cards, any restoration is a negative.
I am active on other boards in which autograph collectors have utilized poster restoration services (linenbacking for stability and edge and fold touchups) for autographed magazine pages.
Two Examples, with touched up folds visible in the Ford.
I recently picked-up a personal grail (personalized to me Clemente program page). I am leaning toward utilizing a poster restorer to linen back for stability, touch up some fold creases, and touch up a distracting spot on his nose.
I am interested in hearing others thoughts on the above.