[Ron Ramirez]

This model actually uses three electrolytics; as shipped from the factory, two were in the same container (27 & 27A), with the third one (62) in a separate cardboard tube, but mounted alongside part (27 & 27A).

This is probably why the cap in your set has three positive leads. However, it would not have worked correctly in that configuration - the negative of (62) needs to go to B- (center tap of the power transformer's high voltage winding), while the negatives of the other two go to chassis ground.

(27) had an 8 uF and a 16 uF cap inside, while (62) had one 12 uF cap.

Owing to the wide tolerance range of electrolytics in the 1940s, you can use a 10 uF, 450 volt cap to replace (27), another to replace (62), and a 22 uF, 450 volt cap to replace (27A).