So, after five joyful minutes of ownership I appear to have broken something...

I'll lay out what I did and what happened in the hope that it might you shed some light on the problem for me.
As a record was coming to an end, the machine started slowing and I put in 30 cranks while it was still running (I think this is where I made my error). The machine increased speed but the handle seemed reluctant to "lock" and felt inclined to spin backward. It did lock, for about 30 seconds before what (to my untrained ear) was the main spring unwinding all at once (The handle did not spin).
Now, I can put about six turns in, with increasing resistance before hearing a clunk and a total drop off in resistance.
Would any of you good folks have and advice on how to proceed?
I did have a look at the main spring, but not knowing what to look for it meant nothing to me. I could snap a few pictures of course.
Many thanks for reading this far!