Detect SSLv3 and Create a list of incoming IP addresses using SSLv3

You should already have what you're looking for with the exception of an additional log line:

when CLIENT_ACCEPTED { 
    log local0. "[IP::client_addr]" 
    if { [class match [IP::client_addr] equals SSLv3_Client] } {
        log local0. "Incoming SSLv3 client: [IP::client_addr]" 
        SSL::profile ADC_LDAP_SSL3 
    } else { 
        SSL::profile ADC_LDAP 
    }
}

or are you trying to log all clients that establish an SSLv3 connection (versus what's defined in the datagroup)?