If you have a Herald and you want to keep those inner muck guards, as i will say that they were quite effective in the rain the other day, you could always replace the Herald ones with Vitesse ones? Although i don't know how much they cost 2nd hand from Spitfire Graveyard?
From looking at the pictures of Tony's, i think i cut mine just a tad shorter, but not by much and as he said it shouldn't make a massive amount of difference.
You can just about see mine on the below pic of my admittedly "in need of a clean and tidy" under-bonnet