def determine_orig_wcsname(header, wnames, wkeys):
    """
    Determine the name of the original, unmodified WCS solution
    """
    orig_wcsname = None
    orig_key = None
    if orig_wcsname is None:
        for k,w in wnames.items():
            if w[:4] == 'IDC_':
                orig_wcsname = w
                orig_key = k
                break
    if orig_wcsname is None:
        # No IDC_ wcsname found... revert to second to last if available
        if len(wnames) > 1:
            orig_key = wkeys[-2]
            orig_wcsname = wnames[orig_key]
    return orig_wcsname,orig_key