I have been transitioning my strikes to AirTites--and have been throwing out the original holders, both small and the newer larger size (the inside plastic nubbins mamy times have broken off). Some of my original strikes had already begun to tone.
In the past, I have offered the old holders for just the cost of postage, but only had one person take me up on the offer. Storage for the old holders would involve too much space.
I have not taken my colored holder strikes out of their original holders, although some appear to be toning, so I may try the suggestions--thanks!