I just caught up on this thread and the thought of the poor souls in the darkness makes me cringe.
I think that you will not fail in convincing them to use the tray, it will just take a little longer than expected, especially considered that they are older than you thought and they might be a bit set in their ways, poor babies.
My guess is that it's little Tansy (possibly Tara) that's still showing how much distress she had to go through by peeing around. Call me a witch if you like! I'm saying it's her because she seems the most shyest and so the most confused. Darling! Of course it could just be the picture...otherwise, cherchez the cheekiest..
They definitely sleep in the outside pen because they missed the fresh air for so long, thinking of it the babies have prob never even felt it on their fur before
BLESS YOU for being there! Where would they be now if you hadn't been round? Still locked up...
And may I just say: Oh, Ms Amelia, you caught my heart!
with that serious face and round puzzled eyes.
Of course little Tara has hit a soft spot too....where does she get her dark eyeliner?
Best wishes, and I really really think that you can't fail in teaching them good manners...you're almost there! In fact, it's amazing how quickly some tlc works