From what I can see in those photos ,those adaptors look very similar to some things we have done over the pat years ,in fact we have a couple of similar adaptor centres to allow us to run centrelock wheels on our Dynapack Dyno.I don't think there was a lot of emphasis on weight back then it was more a matter of making it happen some how .The empasis on weight reduction and lightness of components came about more so in the proceeding years especially with the smaller capacity saloon cars,I know that right up until later times a lot of the cars were over engineered weight wise.Reg Cook springs to my mind as one of the first people to really start paying attention to this area with his first Minis