I don't have any issue with the repair you recommended. My concern is that the brake lines on his car could be 40 years old now.
I have replaced the master cylinder, rear wheel cylinders, the rear axle brake lines, the front brake lines and calipers on my car in the last year. I plan to replace the long, hard line from the front to the rear of the car this winter. All showed signs of general old age and neglect.
The problem is most of our cars sit for extended periods or have sat for years, in some cases, and the brake lines tend to deteriorate over time as the brake fluid absorbs moisture.
I like the restored cars as much as anyone else but my main concern is a safe, effective repair.