'69 Commando V7 Trans pulley brake

[WH_4741 0]

Hi, Was wondering if anyone can tell me more about my transmission pulley brake . One of my Commando V7's has a (extra?) brake band that stops the trans pulley from turning when the brake/clutch is engaged. This is in addition to the brake drum band. My other Tractor does not have the pulley band - just the brake drum band. I don't see the pulley band shown in the parts diagram. I will admit that the tractor that does not have the pulley band grinds into gear, since the pulley keeps spinning. So it would make sense for it to be there - I'm just not sure since I don't see it shown in the parts listing. Any thoughts? Is there a Part number so I can try to get one for my other tractor? Thanks.

Here is a pic showing the pulley band.