Thanks again for the great advice and direction! I changed the cord from 1.5 wraps to a half wrap around the spindle. Then I shortened the spring, and put more tension to it. Now the spindle rotates with a fairly good amount of torque.
When assembled the function is pretty good except when the film strip comes to the point where it has been setting and has a memory bend. I've read where some people flip the film strip inside out to alleviate this. I wonder is this a good way? or is there a better solution?
Another thing I did. Since these shells are painted acrylic, I think they are more fragile than some. At the mounting hole, mine was missing a chunk and there is a hairline crack going up from it. So I got a scrap piece of acrylic and used a fine tip on my solder iron and "welded" in some plastic to fill in what was missing and create a bond to keep the crack from opening up. Check it out: Not sure if I will file it to clean it up, or dremel or touch up paint or what ever to it, but I know it is more robust now for sure.