If you are prepared to deny the old testament, then what you say about the Lydians is true...(now these coins that these”scholars” found may well be fakes).
There was some type of coinage or silver/gold pieces being used at the time of Josph because the story of Joseph mentions money. It also mentions the people of Egypt having exhausted their..”money”, sold themselves to Pharoah and their lands into bondage so that they might live. Joseph established the “flat tax” that 1/5th of all agricultural production would be ceded to Pharoah while the population could keep 4/5ths for themselves. You can bet the “money’ wasn’t just simple lumps of metal but shaped and imprinted.
First, you have to know what a coin is. The numismatic definition, as stated in Webster’s is, “A small piece of metal, usually flat and circular, authorized by a government for use as money.” Another attribute not in Webster’s but usually associated with coins is that they have a standardized value. (and weight when most coins were of precious metal and worth that weight in metal as minted) That distinguishes a coin from medals and other bits of metal or other materials valued strictly by weight or other intrinsic characteristics.
The first coins imprinted with identifying marks by a government to be used as a standard medium of exchange were from Lydia in the 8th Century BC. All other “money” or medium of exchange before that was privately made and the design on it, if any, carried no significance.
That said, there was nothing issued by governments and therefore images glorifying the head of state or other officials would have been completely meaningless and pointless.