Duplicating Echelon's Multi-Volume RAR's -- PLEASE READ IN!!!

I've deleted all my original rar files for my games leaving only the .CDI's
Now I want to get them back.
I want to create exact copies of Echelon's files so if someone downloads files .007 - .009 from me, then adds them to their existing files, they can extract the CDI without problems. (I only have .CDI files on my comp)

I have created the archives (.001, .002 etc), but when I mix them in with some original rar files (.001, .002 etc) that I kept, I cannot extract the CDI (gives file corrupt error) -> which means the rar files I created, are not exact duplicates.

Here is what I know about Echelon's RAR settings (correct me if I'm wrong)
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They do not use the Recovery Record feature
The dictionary size is 64 KB

here is the DOS command line I use for RAR v2.5:
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rar a -mda -v20000 e-xxxxx.001 e.xxxxx.cdi

Does ne1 know what version of RAR Echelon uses (rar or rar32) or what the exact setting are?
Has ne1 been successful with creating exact duplicate RAR's?

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Cheers ;D
Mel