[Sideband]

….and I just noticed that the original smoothing can looks like it was isolated from chassis and just earthed to the bus bar. I vaguely remember doing this to mine when I built them. The smoothing can had a clear plastic cover and I made the hole in the chassis just slightly larger than the diameter of the can so it could 'drop through' by about 1/4 inch. I then earthed the negative tag to the bus bar.

This means you may have to rewire your replacement smoothing caps and earth them to the bus bar as originally done rather than taking the negative connection to the nearest chassis point. You'll have charging pulses all over the chassis otherwise.