Can't be done at the moment, I think that has to do with TB's inability to use html templates.

The best way to cope with this, is to use alternative forwarding, that way the full original message gets mime encoded, so your recipient gets a message with an attachment and opening that attachment will give hime the original message you received with correct formatting, inline pictures, etc.
You can do alternative forward with:
Specials -> Al;ternative Forward

When the majority of your forwards are these kind of forwards, then you can pick it as default in the account properties:
account -> properties -> templates -> forward -> check 'forward messages as attachments'

When you've done this and you'd like to do a conventional forward, then you've got to use alternative forwarding for this.