[Heathkit] SB220 Filament transformer; primary wiring

[Dave]

Greetings;

I am "demodding" an SB220 purchased by a friend sight unseen. I have 
almost completed removing the mods and have started installing several 
of the mods recommended by WA2SQQ.

One remaining issue if the reconnection of the filament transformer. The 
secondary wiring code is per the schematic as is the color code (red) 
for the bias winding. The problem is the primary: Only 2 black wires 
instead of the windings for 120/240.

I assume therefore that the filament transformer actually, in this 
version, connects to one phase, 120 volts, along with the blower motor.

Can someone out there verify this before I (literally) perform a smoke test.

Any other suggestions will be appreciated.

TIA!

Dave, W5WP