twistlock caps replacement

http://www.nostalgiaair.org/Resources/260/M0012260.htm

I have a Twistlock multi-section (3 section) electrolytic I’m attempting to replace with single caps but I’m trying to understand what they are doing here. This cap is dead as a wedge on all 3 connection. The cap is mounted on the chassis top but insulated on a wafer. There is a wire from the transformer which appears to be (+) attached to one of the three twistlocks. Could they be applying incoming (+)voltage to the cap housing and negative(-) out thru the 3 center taps? Please pardon my confusion, this is the first twist lock I have attempted to replaced with single caps.

Thanks,
Ben

The center tap of the High voltage winding is attached to the twist-lock tab which is insulated from the chassis. This is the most negative point. The twist lock tab is connected to 'chassis ground' through resistors R15 (180 ohms) and R12 (10 ohm). This develops the bias voltage for the 6K6 audio output stage and the detector/Avc 6SQ7. The negative on all 3 of your replacement electrolytics will connect to the tab.

Thank you sir.

ben