>>> from base64 import b64decode
>>> token = "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"
>>> print b64decode(token)
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<sso version="2.0">
<id unique_id="
2045723597" src="CN=wsaahomo, O=AFIP, C=AR, SERIALNUMBER=CUIT 33693450239" gen_time="1393252241" exp_time="1393295501" dst="CN=wsfe, O=AFIP, C=AR"/>
<operation value="granted" type="login">
<login uid="C=ar, O=pyafipws-sistemas agiles, SERIALNUMBER=CUIT 20267565393, CN=mariano reingart" service="wsfe" regmethod="22" entity="33693450239" authmethod="cms">
<relations>
<relation reltype="4" key="20267565393"/>
</relations>
</login>
</operation>
</sso>
Ahi tendría que figurar el CUIT respectivo.