Inside the game directory, there is a file name credits.txt that lists the sources for all of the assets used.
The models I created myself are the hovercraft, coolant pump, pipes, bunk beds, refridgerator, light fixtures, sink and shower.
It sounds like you have a good idea of how the mechanics work. I think you are likely to beat the game eventually. If the consensus is that the game is too difficult, I can change some things to make it easier.
In the pastebin below is the strategy I used during testing that usually leads to reaching $30k quickly. I used pastebin to prevent spoiling the fun by putting it in plain text here.