I got a request from my sales team to see if they could some how get their signatures in the MSI plug-in in SFDC.
My only thought was to tokenize all of the information but I don't think all the tokens work. Can they individually upload an image and store it their some how? I don't think this is possible but I promised I would turn over every stone.
You can edit the emails that are published to MSI. That way any of the emails they send through MSI will have the signature available. I would create custom fields for such items as "sales owner job title", "sales owner phone", "sales owner email address" and make them all available for those emails.