o I found Tonchek and found out about the silver cross by asking him. He also told me where his stash was after I talked about the kettle. I got the money from there and also robbed the other sack of money from his body after knocking him out (I still don’t know if you need both sacks of money). Then I went to Andrew to buy the silver cross. I’m on PS4 where that part is still bugged, so I paid for the cross but didn’t get it. And no, the cross wasn’t in the cellar in that locked chest either. Maybe because I had opened (and maybe looted?) that chest long before I had this quest.
I wanted to give the money to Adam in Rattay (first bad decision). Talking to Adam, I made yet another bad decision and chose “I had a few helpers”. So Adam gave me money but the quest didn’t complete. Both his and Andrew’s markers were still on the map. The quest still wanted me to give the loot to either of them, but none of them had a dialogue option about the loot anymore.
If you’re in the same rare situation, there’s one solution, and after googling for hours I haven’t found that one yet (people usually just tell you to load an old save). Go to Adam in Rattay. At least he’s still marked, so he’s easy to find. Knock him out (I guess pickpocketing works too) and steal the sack of money you gave him before. Luckily he still has it on him. The game is bugged, but at least consistent. Obviously try to not get caught while doing it. If you knocked him out, you have to wait for someone to “wake him up” again. Then talk to Adam and you get the option to give him the sack of money again. Do so, but this time choose another option, anything but “I had a few helpers” should do it. The quest completes.