All the paintings except the ones with 6 and 4 had their numbers installed already. Those were the only ones missing.
When you put the 4 in the crypt square, it seemed to unlock something. The 6 may have just been a way to make the 4's spot not so obvious.

So far you have examined 4 paintings, rolled really well, and have determined game room before bright corridor, and study before crypt.
You still have the rope you found earlier.
There are no candles here, but you recall from your earlier investigation of the Wizard's Study painting that you might find one in there.
Your options at this point seem to be:
- study the other two paintings
- go to the game room
- go to the study
- go to the other rooms that you know are harder