For anyone doing this (likely on the TLPs for the focus effect), here's the quick rundown of how this quest unambiguously operates as of 6/2017:
1. Camp Sludge Dankmire in Runnyeye, he spawns at the bottom of the fountain/well near the goblin banker. I can confirm he is around a 4-5 hour spawn. Other sources say things like 28 minutes, which just is not true. I sat at the bottom of the well with a four hour breath potion for almost the full four hour duration of the potion, the pick zone that I was in had been up for six hours by the time Sludge spawned, so without knowing when he died I can say he spawns in no more than 6 hours (if he was killed immediately upon zone pop) and no less than 4 hours. Loot icon from him.
2. Camp Dwigus Lowater in Dagnor's Cauldron. I found him swimming in the northwest corner of the lake itself in DC, I do not know his spawn timer since he was up when I zoned in. At 50 he was a little bit of a fight (was never in risk of death), but make sure you have your lvl 44 nuke memmed and ready. Loot icon from him.
3. Get two platinum bars from a jewelcrafting vendor. Find an enchanter to enchant both of them.
4. Go to Temple of Sol Ro, give your two enchanted platinum bars to Genni on the second floor, she will return two galvanized platinum bars. (I stupidly gave my two enchanted platinum bars to Gavel and he ate both of them, so don't do that or you'll have to buy two more bars and get them enchanted again.)
5. Give the two icons and two galvanized platinum bars to Gavel in the central area on the first floor of the Temple of Sol Ro, he will return chestplate of the constant.
If you're wondering why you'd bother, on a TLP at lvl 50 all of your principal buffs are fully covered by the focus effect, except for AC buff, which is only 1 lvl above (so still gets most of the focus benefit.) Even if you get planar chest which is better to actually wear, it's worth keeping this BP around in classic era on a TLP to extend your buff durations.