I've been tweaking my thruster design, and you can click here to download the latest thruster files (Solidworks). The main improvements are that the thruster has been made a bit more streamlined, the part count has been reduced, and it's much easier to fill the body with oil now. That's not to say that there isn't room for further improvements, but I'm much happier with this updated version.
In other exciting news, a Techshop just opened up about 5 blocks from my house, so it looks like I'm going to have access to some of those fun tools that will allow me to make the more complicated parts like the prop shrouds.
P.S. A note on using these files. With the last thruster design, there were a lot of proposals for different uses of this design. I'm going to attempt to preempt some questions by posting these files under the same creative commons license as OpenROV:
Eulachon Thruster by Ben McCandless is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
If you have further questions, please feel free to contact me.
Update: I've added a STEP file of the assembly to the files. If you don't have SolidWorks, you should be able to import that into most CAD programs.