Just take note that "combo" descriptor is useless on a WIF private key without the compressed flag byte since the other two SegWit output script wont be derived from it.
Otherwise, it'll be non-standard.

You don't have to re-import it as 'pkh' though since it basically did that already, it just skipped the 'pwkh' and 'sh(pwkh)' scripts of the combo descriptor.

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But I have a feeling that you're actually have a WIF with compressed flag byte and just mistakenly pertaining the legacy address as "legacy uncompressed address".
If so, a legacy address can be derived from a compressed or uncompressed public key, not exclusive to uncompressed.
If not, disregard this part.