[Dr.CustUmz]

well shit the advanced reply seems to be broke here so I cant attach images but, your thinking too hard for this =)

in private_messagelist_messagebit
all you need is a var to fetch the avatar, then display that var in the template. in example..

Plugin:

$drc_pmpic = fetch_avatar_url($userid);

then in the template pm_messagelistbit:

<img src="$drc_pmpic[0]" />

now that you got it you can style it however you wish =)

wrap your if conditions for a default pic and all that straight in the template, rather than in the php.

edit: got a pic for you =)