To make the seashell like shape I would make use of the Helix and spiral command. I found these articles which I think you could find quite useful.
To start using the helix and spiral command start out with a basic circle:
Then curves, helix and spiral:
Then select either the helix to generate a spring like shape or a spiral. I have used the spiral for this. Adjust the figures so that the shape is like the one you want.
After this, convert the spiral or helix into a sketch. (I Selected spiral when in a sketch and then convert entities)
Once this is done you can perform a sweep operation. This video on youtube shows how to perform a sweep for an engine turbo, so it could be pretty useful:
Hope this helps.
Thanks for the very indepth and detailed reply. I will try this out as soon as I have access to SolidWorks again, but this guide looks great at the moment so thank you very much.
Hi, thanks for the reply.
This happens to be extremely similar to the shape I wanted to make! Thank you for your help!