Hang on a moment...
Let's take another look at that mainspring...
Do you see what I see, friends? Or rather, do you also not see what I don't see?
Can it be? That looks suspiciously like a hole that shouldn't be a hole.
When I first separted the machine from its base I wondered if I wasn't looking at more holes than screws and now I see a space that seems to be crying out for... something? Is there something that is supposed to go there that catches onto the spring to set the tension. The hole leads through to the mainspring drum and I can definitely see the telltale signs of metal that used to touch metal.
I could be wrong. I don't really know anything about it, but I have to go with my instincts on this one.
A missing piece of the puzzle. Hmmm... What to do now?
I am in the process (25 m 22s and counting down...) of buying a second, similar machine from ebay that I can use to compare with Virginia's bits and pieces to try to get a better understanding of how she is supposed to work and how I can fix her.
What I need here is a bit more knowledge and experience with typewriter mainsprings on older machines.
Besides its much too sunny a winter's afternoon to not be tinkering with typewriters, isn't it?
That means, ladies and gentlemen, that it's time to enact...
THE CUNNING PLAN! [Da Da Daaaaaaaa!] etc.