Concerning Ballig Bridge, here is an excerpt from the old site written by nickname alf:
Photo from Bob Holliday's book "Racing Around the Island" - Ballig Bridge 1930. The caption to the photograph states that the bridge was widened, straightened and flattened in 1936. For the record the rider is Ernie Knott on a Rudge on his way to 7th in the 1930 Senior.