What is the ruling on using and keeping gold liras from the British Mandate period that have engravings of a human and a horse, and dealing with them as currency? And what is the ruling on wearing them or hanging them for adornment?

It is permissible to deal with money that has pictures on it. Jurists have stipulated that the pictures on it fall under the category of "degraded images," the use of which is not forbidden. The predecessors (Salaf) dealt with such currency without objection. Sheikh Ibn 'Uthaymeen, may Allah have mercy on him, was of the opinion that there is no sin upon one who carries it out of necessity, to facilitate matters for people and remove hardship, for Allah Almighty says: (Allah intends for you ease and does not intend for you hardship) and He says: (And He has not placed upon you in religion any difficulty). As for wearing or hanging them, many scholars have gone to the extent of prohibiting wearing anything that has a picture of an animal, even if on a female, and also prohibiting hanging it.