I'm looking to get the achievement to restore the former glory to the thieves guild and to become guildmaster. Does anyone know the deal? Here's what I think I know:

-complete 5 side quests for Delvin/Vex in a certain city=special request
-complete 5 special requests in every major hold to become guildmaster

Is this correct?

You've also done the main questline? ...up to and including dealing with Mercer?

You have to do the main questline, including returning the skeleton key, then 5 jobs in each of the 4 holds (Riften doesnt count) - Solituse Whiterun Windhelm Markarth. Then the 4 special jobs. Then you have the ceremony, receive your armour and key, and the achievement should unlock.

link http://www.uesp.net/wiki/Skyrim:Under_New_Management

Oh, yeah, "each" city. I didn't notice you said "certain".

I have done this with one of my playthroughs but was disappointed that the guildmaster's reward chest does not seem to refill with gold or loot. I got a one time bonus with the chest then nothing.

huh. it always refilled for me.