ZW whistle controller?

[dennyblock]

I'm replacing the rectifier discs in an old ZW 275 watt transformer with diodes. I need to know if the end with the painted stripe goes towards the metal bracket or towards the switch contact. I did an internet search and found several pictures of it either way but that can't be right because you reverse polarity to switch from whistle to horn! I know stud diodes would be easier but I already have these. Anyone know the proper direction to mount them?

[chuck]

Actual schematic is on the Olsens Toy train site.

http://pictures.olsenstoy.com/cd/transfmr/psvw1.pdf