[Mailman-Users] listproc archive conversion

i have a bunch of digest archives from a listproc-6.0c server that i need
to convert to mailman archives.

the problem is that none of these archives are in unix mbox format. that
is, there are no 'From ' separator lines (does this mean they are not
rfc822 compliant mailboxes?). i think the only consistency about these
old archives is that each message begins with a 'Date:' header line.

i have used the mailman arch program to convert majordomo archives to
mailman so i'm familiar with arch. should i be able to use arch to
convert listproc archives?

i could use the 'Date:' line to separate the messages but would i also
have to add some other header information in order to use arch?
if so, what header fields, specifically, would i have to add?

does anyone out there have any advice, tools, etc., for converting
archives or massaging mailbox files or digests to get them into a format
that arch will accept?

thanks for any help you can provide!