Skyrim Thieves Guild Bug

I know my game is glitched, because it's been well documented on every wiki and forum I've looked at, but I need an answer.

I've gone through all the mainline quests, killing Mercer, returning the skeleton key, and doing side quests until I've completed all the special quests in Windhelm, White Run, Markarth, and Solitude. I even did the quest to deliver moon sugar to the Khajiit caravan. I've completed "Under New Management", but I've never got the "Tribute Chest Key" and now Bryjolf won't talk to me. I got my guildmaster armor and Delvin refers to me as "Boss" but Bryn still won't talk to me or give me the key!

I always save over my last save so going back is not an option but I am playing PC so console commands are.

And I know there's hidden dialogue they wrote into the game, recorded etc. But it still won't come up because of the glitch.

I can't install the mod that opens up the dialogue so that option is out.

Is there any hope for my dilemma or am I out of luck? Are there console commands for this? If so, what are they?