Well, there's your problem.
If you have the tenanting option in your licensing you might, and I stress might, be able to assign source 1 and MOH for the stations. Source zero will still be active for devices that cannot be tenanted so this is far from a solution but might suffice as a temporary measure.
A better measure might be to FTP into the 3300 and grab the original source file and then replace it.
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What's most important is that you realise ... There is no spoon.