you should try making that many boards from base parts, then you will know the meaning of forever lol!
No kidding. 70 boards with 82 pins to solder on each board is a total of 5,740 pins to solder. If the boards were donor boards and the masked rooms had to be removed that's another 5,740 pins that have to be desoldered before you can begin soldering.
With that amount of repetition you get good at it, but it's a huge endeavor to do.