Machining for Porsche Fan

[vdubfund]

Hello to all
Does anyone know how to ,and or willing to share the details on machining T-4 case for a porsche style fan? I`m in Japan, where T-4s aren`t to popular. I sent a picture to a competent VW machine shop in Tokyo, says he`s never done it, probably could though.
I really don`t want to have to send my case to either Germany or the UK to be machined.

Also this part (see attchd) came with the porsche fan I just bought.
Should, and can it be used on a T-4 porsche fan shroud??

Thanks to all