r1100s 2001 mfg dates?

[billpierce]

I have a S that was mfg in 2001. My question is how do I tell what month it was mfg. in?
The vin # is WB10432A21ZB51737

There was a change in the seat mount and thats why I need to know

 

[billpierce]

Just figured it out. But in case anyone else wants to know.

http://www.sargentcycle.com/bmwwsrstech.htm