During a re-cataloging of my ids I had the opportunity to take done all the aircraft, brush them off, photograph them, and rehang.
To my surprise I found several post War grey ids were 'melting'. These have been flying in my "Plane Room' for over 10 years now in year round air conditioning.
I discussed this with Bryan Brown, our expert of IDs, and he confirmed it, The Seamaster is notorious for it. What a shame.