It's possible to make one yourself with the CS/TES4Edit and Nifskope. In the Construction Set or TES4Edit, just change its type from BladeOneHand to BladeTwoHand and in Nifskope change the sheath position from side to back.
when you say it's in the main room of the imperial palace, do you mean i where chancelor Ocato is sitting ? because the sword is not there and i can't found in the area.
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