That sounds like a brilliant idea, and a wiki is just as good as anything for collecting this sort of information, and I quite agree the percussion is usually the most diverse and tricky for making these sorts of determinations.
* Yes, one page for instrument/family, and use the associated Talk: pages for sorting out discussions about favourite models etc.
For relatively unusual percussion, links to the most frequently performed works that need them, e.g. wind machine => Alpine Symphony, Daphnis et Chloë, etc.
antique cymbals => Prélude l’après-midi, Berlioz Roméo et Juliette, etc.
perhaps ditto the more unusual winds, e.g.
basset horns => Mozart Requiem, Strauss Elektra & Rosenkavalier, etc.
I'll defer to the wisdom of Feldmahler as to whether this would be better hosted over at IMDBP rather than IMSLP.
* For individual works, a "percussion" template for the IMDBP pages could be a handy way of summarising the personnel/layout/instrumentation issues.
Again for example, I edited a symphony last year which had numerous issues like the ones you raised, e.g. celesta used for just 4 bars in the whole 40 minutes, playing 8 x 3-note chords! Can the timpanist switch to gong in 1 bar of Adagio? Numerous other "quick switch" issues. Would the harpist be prepared to play triangle at the end of the second movement where it appears you need 8 or 9 separate players? (Timp., B.D. + Cymb., S.D., Tamb., Tri., Bells, Xyl. and Glock.!)