David Forsyth wrote:

Would it be possible, though not necessarily practical, to make a receiver
for the modern FM broadcast band, using only pre-WWII tube technology? I
know they had FM on a lower frequency band at that time.

I have a few pre war FM sets, see
http://www.geocities.com/wa2ise/radios/fm45.html

What sorts of
tubes could one use from the 1930's to make a receiver that could tune in
the modern FM band?

Focus on the front end. Once you get to the IF, then my Emerson 460 pre
war set
would have the same technology as your "what if" set. I think acorn
tubes were pre war,
and were designed for VHF service. 2 or 3 such tubes (one RF amp,
another local
osc, and the 3rd the mixer) should make a good 100MHz front end. The
above Emerson
had an IF around 4 or was it 8 MHz, used octal tubes like 6SG7 and 6SH7
and a 6H6
for an FM detector.