Spent some time cleaning up the metal ball guides. Most were pretty filthy but also had ball tracks worn in them as shown in the first two pics.  I cleaned them then used wet and dry grade 240 followed by 400, both wet with windex.  It hasn't removed the tracks completely but looks a lot better - third pic.  Also gave the same, but a quicker treatment to the the under apron metal work.  It's very nice to be reinstalling clean bits.

Not sure about what to do with the bumper caps.  I have seen a Flash with the translucent blue caps that looked ok.  Haven't compared the original ones I've got to the new bases and skirts, but I suspect they'll look pretty shabby.  First I'll try some novus and maybe a touch up of the red in the stamping.  I'll most likely put a led in the them so that might brighten things up a bit.