Does anyone have any ideas how to relicate this weathering pattern on resin?

[Birdie]

I'm trying to replicate this weathering/aging pattern on cast resin. I've tried cold casting the part with aluminium powder and using dark washes and casting in dark grey, spraying with silver and scratching off the paint where relevant, without very satisfactory results. The pic of the original the silver looks quite dull, but is shiny onscreen. The brown center parts are not a problem.

Anyone got any suggestions what might be a good technique?

 

[TazMan2000]

How about spraying, or casting it grey and using a Molotow Chrome pen to make the silver parts? Use tape to remove areas that have too much silver.

TazMan2000

 

[Birdie]

I'll give that a go, thanks