I think I've just worked out, what Si was on about with his warning.
Once you get started on this polishing thing, it becomes an obsession, to remove every little micro-scratch, until you can see your own reflection in it.
Was in Bunnings yesterday, but finest grit wet & dry in stock was 1200 grit. Grabbed a few sheets.
Off to SCA then, as I had some credits, which were just about to run out. Grabbed some metal polish.
Last night, for 40 minutes, I rubbed one end of the cover, & then polished it, & the difference was amazing.
Unfortunately, every time I've used my mobile phone this morning, I had to revert to my pin number for entry, as my finger print is no longer recognised !
"It's a slippery slope" indeed. I've just instructed myself, to not even look at the "timing chain cover". 🥵