Great article. Proves what I've known for about 5 years now...that vintage gear was "made to be repaired" which has resulted in it lasting for 50+ years. There are still a few of us around that know how to fix the old stuff - it's great fun and, having been inside nearly every make from the 60-70's, I can say that they are generally very well designed and will sound as good or better than most comparably priced modern gear.
Everything was "made t be repaired" at that time but the main thing is that the manufacturers have changed their model from being willing to providing service parts to only wanting to sell finished products. They no longer authorize and train service people all over the country, partially because people aren't learning to repair electronics in the numbers they once did. Also, printing and shipping service manuals would be prohibitively expensive now- they changed to CD-ROM in the '90s and once the internet was live, to web-based training, rather than people traveling to major cities where the manufacturers had some kind of headquarters or factory service center. In addition, the new equipment uses digital circuitry, which is completely different in how to diagnose and repair- some parts can't even be removed and re-used because the heat from the iron destroys them. Small parts are installed by machine far faster than humanly possible and so much of them are surface-mount that it's just not worth the time to replace individual components, so most repairs are board and module swaps.
One thing I liked in some brands of equipment was the way they used linen cord to wrap wire bundles, rather than plastic anchors or tie wraps- it was so orderly and neat.
