[ARC5] BC-221E converted to loctals and high voltage?

[Tom Bridgers]

Recently purchased a BC-221E that had been converted to loctal tubes and had 
a add-on power supply that fed about 350 volts under load to the meter.

Does anyone happen to have any information on why a BC-221 would be 
converted to loctals and why they chose to run the meter at such high 
voltage? For example was this suggested in QST, CQ or other type radio mag's 
of the 50's?

I have several BC-221 type meters and this is the first one that I've 
encountered with loctals and high voltage...
Thanks in advance for any comments or references,
-tom
p.s. --  The meter also had been installed in a home-made, wooden cabinet --  
which I think is pretty neat.  The upside is that it's much easier to 
operate than with the original cabinet, but of course the down side is it's 
not original and probably has less value as a collectible.