Add .psd brushes to Gimp

[Box-weasel]

I have been looking for this for years.

1st, DL Windows executable at the bottom of this page:
Tor Lillqvist--PSPI: Running Photoshop plug-ins in GIMP

2nd, unzip the file and put the .exe in your Gimp/plug-ins folder

3rd, DL some psd .abr brushes & put them in your Gimp/brushes folder.

FBS has a gr8t set of weathering brushes at M4T/Essential files/skinning utilities.
Also look here: Arc's Rivets + Metal Brushes by ~Arcy-is-distracted on deviantART

and here: 30+ High Quality Metallic Texture, Pattern, Brushes and Photoshop Tutorials | Photoshop Tutorials

Open Gimp--I have v.2.67 and look under filters and browse to the brushes folder to enable it. This may help: PSPI.exe -- for PS plugins by ~iceytina on deviantART

Click on the brush icon and have fun.