The new bobbin case has arrived. I was disappointed that is wasn't a Singer OEM part as it was advertised.
However, I installed it and guess what? No more nesting!
I even went as far as removing and disassembling the electric motor to give that a good cleaning (it was struggling).
I also overhauled the foot controller, what a difference.
This machine now stitches beautifully and runs fast as it should.
Now to find a new home for it.