Yes, I am prepared to do it on principle...as long as I am not risking more than £70!You are because the penalty is £140.
They might be prepared to accept £70 even after unsuccessful reps but, as you put your statement, then the answer must be pay before 25th because to progress means risk.
If you want to accept the risk, then I ask you to look at GSV(if this reflects what is current then this would be the standard of signage available to an adjudicator:
Find local businesses, view maps and get driving directions in Google Maps.
IMO, it is compliant and visible.