Oh I see. I had used the wrong query. "vCal" routes directly into Net::IPv6Addr which is an obviously broken response. I didn't yet know that "iCal" is a newer version of "vCal". Anyhow, it just looks like none of the listed modules do what I want so either I implement them myself or find another implementation in a different language.
I had hoped to pipe internet e-mail messages into a script, use MIME::Tools to iterate over each of the MIME entities and extract out the vCal/iCal parts for processing by some yet unspecified "other" program.