How to make a professional looking controller port mold?

[Macabre]

I've been putting this thing together for a while now. Here and here are two shots of a dreamcast expansion unit I've been putting together, that supplies the controller cords to the main system. Ignore the dust, as I'm a time-short individual and finding the time to work on my projects such as this is hard

I've made the cords very secure with zip ties and some glue - they won't be falling in or out of the lower shell any time soon. But I'd like to make their entrance to the lower shell look...better? (where the electrical tape is).

I once had black hot glue sticks, and recall those being moderately easy to use. My first idea was to use that to cake up the holes where the plugs were until it was lava-hot and smoothed out nicely (not flat, still a concave dip into the socket).

I don't know if there is any easy way to vacuum seal something better looking? Are there any other ideas or methods I'm unaware of?

Thanks in advance for any help!~