1) The forum's search works pretty well.....
2) Polishing the block is a lot of work. Most people clean them up pretty good and paint them and then polish things like the rocker covers, clutch cover &c.
3) The original finish on the 500 engines was metallic silver paint on the main part of the engine with the rocker covers & clutch cover polished & clear coated.
The original finish on the 650s was black on the main part with polished & cleared covers and a black band across the rocker covers. I think the main part may have been powder coated because it is pretty tough stuff.