B&W D1 vs D2 Diamond D1 vs Diamond D2

Hi,

Is the bullet color different. I think D1 has Black and D2 has silver.
http://www.oocities.org/drpaulng/B_W_Phase_Plug.htm

I see that D2 parts are expensive than D1
http://www.bwgroupsupport.com/parts/partslist-bw

If i am buying. How to tell one from another.
Does it say on the back 805D and then letter D in small box just like they did in the 805S and then letter S logo.

Thanks