Lovely restoration job you've done there. I've just acquired a 1971 Senior with a blue hood for £20, in very good condition and all original, though clogged with 47 years of dust. Now it's been cleaned, the only thing that's got damage is the plastic hood. Lots of shallow scratches, but some deeper gouges too.
What is the best way to deal with these please: use a cutting compound (T-Cut?), then polish, or fine wet and dry sand and then polish? I'm worried that once I start sanding, however fine, I will never get the gloss finish back unless I then paint it. And painting over plastic seems like over-restoring it, unless you are looking for an 'as new' result, which I'm not.
PS: interesting to see that your 652 has a white painted belt cover plate: all the UK ones I've seen are polished metal.