Well, by my calculations, we've accumulated 11,115.35 gp of wealth so far (please check that if you have any inclination). Divided by 6 (for our 6 "real" party members) is 1,852.56 (rounded) each. That does not account for either Thomas or Ciaran's late arrival.
Given the distribution to which we've tentatively agreed:
Deren has 2,826 gp of loot (cloak, dagger +1, mithral shirt)
Aeron has 1,981 gp (mwk plate and hvy mace +1)
Zirat has 1,325 gp (plate +1)
In addition, Deren needs 110 gp to resize his armor and Aeron needs 165. However, Deren should be able to get 87.5 gp (175/2) for selling his armor, and Aeron should be able to get 300 gp (600/2) for selling his. So, Deren needs to add 87.5 to his total loot (2913.5 total), and Aeron can subtract 135 (1846 total). Assuming that Deren pulls his resizing expense out of the total loot, and Aeron puts his surplus from selling back in, that makes the total loot found unchanged.
So, the total of remain loot everyone should get is:
Deren: owes the group 1,060.94 gold
Aeron: 6.56 gold
Zirat: 527.56 gold
The rest of the goup: should get 1,852.56 each, notwithstanding what Deren owes the group. And, as noted, this does NOT account for giving Thomas anything, and DOES give Ciaran an equal share.
After accounting for the money Deren owes the group:
Deren: will be even
Aeron: is owed 6.56 from Deren
Zirat: is owed 527.56 from Deren
Merrick, Ciaran, Jebediah: each get 1,661.12 gp from the current loot and Deren owes each 191.44 gp
(And, after looking over the math, I appear to have a discrepancy of 47.5 gp between what Deren owes. Someone should check my math, if we are concerned. I'm too tired to redo it now. I KNOW some of the discrepancy likely came from rounding, but I wouldn't expect 47.5 to come from my rounding to the nearest 0.01 gp.)
I CERTAINLY have no problem with Deren having more of the loot than the rest of us. After all, we'll be better of with him using the items we found than us selling them. And, while it is a fair amount, in the end it should work itself out. Other considerations are that Ciaran just got some free spells, and (negatively) Thomas should get something. But, at least, this seems like a good baseline from which to work (assuming that my math is correct AND that I accounted for all the items we've found).
Finally, in my accounting, I gave all the excess cash to Merrick, Ciaran, and Jebediah (as shown by the fact that Deren owes each of them 191.44, but owes Zirat 527.56). I'm assuming that this is actually movable, and could change if we decide to give Thomas a share of his own and/or decrease Ciran's share. But, as I said, this is a baseline from which to start.