My grandfather used to go out and buy new tubes occasionally. He bought some really good ones, because they have been in there for at least 45 years. The only problem parts were the filter capacitors - I replaced them around 1965, and nothing has been done to the set since.
I plan to refinish the cabinet, in spite of the perceived value because I intend to keep it. May as well make it look nice.
There is some confusion as to what a dynamic speaker is. Traditionally, it is any speaker with a field coil. The field coil had two major functions. One is to supply a magnetic field for the voice coil to work against, and the other is to help filter the B+ supply. Sometimes you will see "dynamic" written on a permanent magnet speaker.