There are a few photos of the Shields around but unfortunately none clear enough for a definite answer. As far as I can tell they have made some kind of return flange and used that to bolt it to the L-Beam that re-enforces the outer edge of the horns.
There is one slight problem.... these are pictures of Sir Reginald (Mk IV) which has different sandshields as Otazel Mk I ........if you compare the pictures,they look quite different
It looks like Sir Reginald has some kind of pressed steel plate which extends to the idlerwheel
Otazel has what looks like a steel 90 degree angle plate which stops just before the idlerwheel ......