I found this set of NOS Olympic 15 inch green-walls about 20 years ago.
Made in Australia during the 1960's, the set of 5 are close enough in colour to the Velvet Green trim seals on the 1500 'S' that I will have them installed on the original notchback wheels at the appropriate time in the future.
One of them is a bit dis-coloured as you can see, so that will be the one that ends up on the spare wheel.
I originally bought this set of NOS green-walls along with a set of NOS red-walls and a set of NOS blue-walls. I wish I had never sold the red and blue ones on but anyway, I have managed to keep the green ones and those are the ones I wanted.