Hello
I have review the project description,As per which you have an existing Drupal 7 based custom developed message module & now you are looking for a Drupal Expert who will assist you on make some modification within that module.
As a Drupal Expert,I have can customize its module,plugin,functionality & also can custom development as per the requirement.
I would like to tell you that I am working on Drupal Platform from last 7 years.I have worked on its different versions such as D6,D7 & Now Latest D8.
I would like to discuss the project details with you,so that after i will suggest you time,cost estimation accordingly.
Thanks & Regards
HS Virasat Solutions