I have been converting a lot of these manually, just changing the is_fileless field in the db table to be 0 and then uploading the zip file again, even going in to update the download count and version number to match what I require.
I think to automate this inside your plugin would be too much work just for what I need. I appreciate your offer but unless a lot of others show interest I would just keep your plugin as it is and focus time on other things.
Appreciate your offer to look at it. Perhaps we might work on something else sometime