[Richardgr]

The beauty of older things, for me, is that they were not designed with built in obsolescence. Look at those pre-war electrical appliances - they cost a fortune, but it was a long term investment.

Inherent with something that does not have built in obsolescence is that it has to be easy to maintain. The circuit diagrams were often affixed inside, and components were generic and readily available.

Any set that anyone has from the 1930's is likely to have seen the business end of a soldering iron at some time, and that means contemporary replacement components from the time it was repaired.

Therefore a consequence of owning a device that was built to last forever is that it was never intended NOT to be improved over the decades of its life.

There are some sets that were hardly used and put away, and are museum pieces, and those are a special case.