MauiK3, the mechanic explained that leaky fork seals may compromise front bake pads with oil resulting in not being able to stop quickly enough. I can understand that.
So I figured that I could just swap out the front forks with my parts bike, also a 1974 cb750. However, it had been modified during its time into a cafe racer style and a previous owner installed shorter forks. Darn!
The rusty tube is original to my bike, the shorter tube is from the parts bike.