I'm not sure what you mean by "converted to MIME inlines" given that
MIME attachments are always inline :)  In any case, if you have a new
enough 1.8d beta, the MIME attachments in a given message can be opened
by clicking on their links in the web archive interface:

 ************************************************************************
 * [non-VM] Enhanced WWW archive interface (clickable attachment links) *
 ************************************************************************

 Under version 1.8d, the WWW archive interface has also been enhanced to
 provide point-and-click links for e-mail attachments sent to lists.
 Assuming that a user's browser has a given MIME-type attributed to a
 helper application, he or she will be able to open attachments of that
 type which have been sent to the list in the appropriate application.

Nathan