Possible Clues:

• No joke where French knocks out English in set
• Earnest, sincere
• Far from funny
• One's entombed in watery grave
• Not a light start for 23 across
• Bearing the right credit-notes is important
• Grave foreign coppers holding back anger
• Grave Stock Exchange heads the monarch promises to pay
• Rise round us from the grave
• On the level