Is what was agreed upon regarding the equal division of profits, along with bearing the losses resulting from delayed sales and currency devaluation, considered valid and permissible (halal), or does it involve injustice to the other party?

Your partner does not guarantee against loss except in cases of transgression or negligence. Since the sheep were sold for sixty thousand pounds and the capital was fifty thousand pounds, your profit is ten thousand pounds. Half of it is for him and half is for you; so he gets five thousand pounds and you get five thousand pounds, in addition to your capital of fifty thousand pounds. Whatever your partner gives you in excess of your right, out of his own good will, you may take it. But whatever he pays you out of shyness or due to pressure, you are not permitted to take it.