[Phlogiston]

Preservation is the reason, only reason, that I don't change them all out. I want to keep as much of the original radio as I can. So anything that I think is serviceable for the next ten years or so stays. That which is replaced is replaced with a fabricated original-looking replacement of better value, meaning higher voltage rating or much higher wattage rating in the case of resistors.

A few of you will think "ten years". Yes, that is why I avoid using new electrolytic capacitors whenever possible - 10 years! Instead I use polypropylene film caps. So, See, it goes both ways.