Another option (think of it as a safe guard), is to put everything in the mystcraft world, in ender chests. With 4,096 different combinations, you can safeguard any collection. Because even if it somehow becomes corrupted, you have the safe guard of being able to drop another ender chest in the overworld to retrieve all of your goodies. This is quite expensive, but is really the only fool proof way to get them.
Another thing to note is, even if you don't have chests in the overworld, and the world becomes unstable/corrupt, you can still drop the appropriate chest after and retrieve your goodies
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Hope this helps bud.