Brass or silver

Can someone tell me the correct type of piano hinge for the brake and clutch access cover is it brass or silver?

 

Brass on my GTS (07412).

 

Brass on mine originally. I think the replacement I bought was steel.

DM

 

Brass on my Euro Gt

 

Brass on my 69 L-series.

 

I have located the original brass hinge, another question though ,what is the correct number of pop rivets and there positioning,I have noticed in my search various scenarios 6 rivets 3x3 and directly opposite each other or 3x2 and should I use brass rivets.

 

Here is a photo taken from the back of a new OEM trunk reveal panel and brass hinge. The hinge is obviously hardware store variety. They just chopped it to length and rounded the 4 corners with a grinder. Notice the hardware store hinge had mounting holes close to the center so they just moved the center holes over a bit. It doesn't look like measuring was a big issue.
The pop rivet are 1/8" steel.
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Here's a front shot of the OEM cover and rivet location. I bought it from new from Algar in 85 and have never installed it.
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