[R-390] Question about R-392 1961 Dubrow COntract & V201 & V202

[Anderson, Craig - Ext. 1365]

After many R-390A's and SP-600's I finally decided to acquire an R-392.
I was lucky to find a very nice 1961 Dubrow contract radio with
connectors and noticed that V201 and V202 are 26FZ6's instead of the
26A6 listed in my 1954 edition of the tech manual.  Does anyone now the
reason for the change to the 26FZ6?  I have two tube testers and even my
Heath TT-1 with the 1976 tube data supplement doesn't list the 26FZ6.
Any ideas how to test these?  Also, it came equipped with the factory
Dubrow solid state audio replacement. but I am getting no audio.  Is the
schematic listed on "Provero's" website as the "official schematic" of
the solid state audio replacement, the correct schematic?

Craig W9CLA