Check this out- it does both
LegacyMULConverter-v4. UOP Packer/Unpacker
allows you to convert LegacyMUL UOP files back to the old MUL format and back. Source code and documentation is included. https://code.google.com/p/runuo/downloads/detail?name=LegacyMULConverter-v4.rar&can=2&q=
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Author-Epila
UOFiddler UOP Extractor plugin (version 0.1) - UOFiddler plugin to extract UOP files
Works with UO Fiddler