I did a bit more grinding and filing last night and Western Talisman has now been able to complete laps of the outer circuit and go through the crossovers without derailing. A little more work and I hope to be able to use it on the tighter inner circuit too.

Continuing the Western brake saga, I have now cut away more of the brake hangers to clear the skirts. This has ended up leaving the leading ones unsupported, so the pull rods are supporting them, rather than the other way around! However, Western Talisman has now completed several circuits without derailing ... on the inner, tighter radius circuit! 

I still have to touch up any unpainted edges and paint those brake shoes and brass wire pull rods. I may try to add some wire supports behind those leading shoes on each bogie just to tighten things up a little.

Overall, I'm quite pleased with the result as the Heljan model always looked a little bare around the bogies before. It is now a fitting companion to the Dapol/Kernow model and almost indistinguishable from it at normal viewing distances.