The outside of the vanes I cleaned with brasso. I made a simple cleaning pad to clean between them. I took a strip of self-adhesive green felt, and folded it round a piece of thin card. This fitted between the vanes, and cleaned it very well. For the brass shaft between the vanes, I put the shaft end in a vice. Wrapped a length of thick string soaked in brasso, around the shaft, (two turns) and dragged it back and forward to clean it up. The main frame was sprayed with matt primer aerosol obtained from Halfords. It didn't take very long, maybe five minutes to take it apart. Half an hour to clean it all up. Then, after paint was dry, another five minutes of so to re-assemble it!
Once the retaining plates were unscrewed from the ends, the moving vanes slid out diagonally.