Your error was actually fairly trivial: you hade overlooked that the tag looks like this:

<Object Database="[bos_sommar]" Schema="[dbo]" Table="[currencies]" Index="[pk_cur]" IndexKind="Clustered" />

That is, the index name is quoted in brackets.

I changed the procedure, to have this line in the beginning:

SELECT @IndexName = quotename(@IndexName)

And then I removed two invocations of quotename that you had, and now I got output from the second query.