Since new spokes would be needed, and OP may have no use for the old, they could just be cut out without significant labor. Admittedly cutting the first few spokes cans stress the rim until the overall assembly loosens up, but folks do this all the time without rim damage. I've personally done it many times without any harm to the rim that was detectable during the rebuild.
On the other hand, I agree that keeping the spare wheel intact, perhaps as a trainer wheel or just a spare has a lot of merit.
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Robert
No matter where I go, here I am...