You're welcome Ron. They are readily available Volvo Part #273500
http://www.classicvolvoparts.co.uk/p...ID=47&scID=129
B suffix indicates repro with B=Brookhouse I believe.
As you can see, a new regulator is £20 more than an exchange dynamo!
VW ones have push on tabs and may also have a lower amperage rating. Often made in Brazil and cheap and maybe not as good as German Bosch.