Trying to work out how this was done, any ideas

[Buck2467]

Hi guys, currently working on my first imperial knight, never done a mini so large, I'm trying to go for a realistic feel to this and so I had a look through cmon for inspiration. Then j found this guy. It looks fantastic but it's not what I'm going for, however, I love how he's done the blackened metal on the pics of the rear, any ideas how to replicate or at least get something similar? Is it just black working up some subtle grey highlights then a rust brown wash? Or something more? View attachment 44826

 

[MAXXxxx]

looks like someone got carried away on their NMM

that said: yes it's basically grey shaded to black highlighted to a lighter grey (with some pretty light grey edge highlights), then washed/glazed with a brown to get the rust effect.