in the 80s when I worked at a shop we noticed that a lot of the wieghts for some companys were right on. They would measure a 21 inch frame but at least it was fairly accurate. Some other brands were not even close and you would have to strip it down to meet their advertised weight..it all depended on the brand.
__________________
From Illinois. Collector of many fine bicycles from all over the world. Subscribe to my Youtube channel. Just search John's vintage road bike garage