The 2 amplifiers will have the most gold content. The gold plating will be very thick.
On the Fujitsu component it looks like the gold plated lid is attached with a gold tin solder. That is what makes the gold content so high. If the Mitsuz has a silver colored line between the lid and body the the component then it will be gold tin solder as well.
I am not sure about the isolator gold content. The 2 blocks on the right side of the picture may be gold plated aluminum.
From the looks of the blocks they looked tarnished or maybe has metal migration making the gold plating tarnish.
Most microwave and radio frequency items that are gold plated will have a thick gold plating. The gold plating is used for shielding.
Weigh them up and see what you have. If you aren't going to keep them put them on ebay.
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