Brainy Pete had a silver trophy...

[factotum]

The real question is why nobody stole it (and the gold ones) right away...They are all a bunch of thieves.

Because they already know that everything in that house belongs to the Guild once Pete dies, and it isn't worth getting on the wrong side of Bozzok to get a short-term cash injection?

This is off-topic (and maybe discussed) but Brainy Pete says to the guildmembers that he just wants to get to his den (where the weapons are) Is it possible that he really was going to mount a rescue?

If he was going to rescue them, why would he have sold them out in the first place? And no matter how good a shot he is, I doubt Pete would be a match for the whole of the Guild even with his eyes back.