hi old gal, will try to help, but not v good at alternative clues lark....
20a - think of a chess piece
22a - another word for rely on - ***** me, I'm a doctor???
13d an old fashioned case [I think of it that way anyway!] outside another word for also - sum total to trash
15d boys' name surrounding another word for defeat....
Don't know whether I've muddied the waters, or what...
Nightowl, I think the 'new' Wallender is the original Wallender, who appeared in the first series, which I didn't see, but they did show a couple of his episodes not so long ago - deffo not the English version - altho' don't hold me to that.....