XDR to XSD converter?

We have an old XDR file that we'd like to convert to an XSD. Any comments as 
to what's out there (if anything)?

We've tried a few avenues already with no joy:

Tried the MS XSLT based option:

http://www.microsoft.com/downloads/details.aspx?FamilyID=5F6505A1-359E-47BF-8963-F4AFFAF87566&displaylang=en

The XSD it generated started with 1000+ errors which weren't too tough to 
fix - coupla hours of work - but then when validating a known-good XML 
against it - 900 errors. Ahh, no.

The IBM Java tool at:

http://alphaworks.ibm.com/tech/xdrtoxsd

is retired, source long gone.

Tried the Visual Studio xsd.exe tool at:

http://msdn.microsoft.com/en-us/library/x6c1kb0s(VS.80).aspx

but that tool dumbed down the schema, for example, turning the enumerations 
into type xs:string.

Maybe some XML editor out there can do it? I couldn't figure out how to make 
Oxygen do it.

Anybody tried the SQL Server tool?

Any other ideas?

Thanks in advance,

Karol