Using Harpic is a great start. Check the youtube vids for details.
If you have a Dremmel, there are a range of pouring pads you can get that work excellently with Autosol and eliminates 90% of the elbow grease. If you don't have a Dremmel I'd buy one!
There are also soft mops for Dremmels that will bring the final shine to better than new, also with a little autosol or gentler metal polish like Peeks.
Blue off gloop is cheap on ebay and it keeps them shiney.
I'm curious about the pickling though?