The Moss crank pulley is two parts,the sleeve and pulley,which is sandwitched in rubber to dampen,and the seal sleeve that must be pressed together to form complete hub.It also is slightly smaller diameter and you need to stamp you own timing marks. Pulley is 10x8mm and I think they sell the components separate.I thought the kit and hub was nice,and made for an easy conversion.
I think VB had 1/2(and you want pulleys to match)but no fan eliminator bolt.Moss is for no fan hub.
There is on other company in England,I can look up name if no else posts.
Tom