In order to use the centre sticker you do of course require centres to stick them to, originals of which are a) quite rare and b) correspondingly expensive when they do turn up.
Having had a set of original wheels refurbished I have found that the (plastic

) centres sold for the modern repro D1s don't fit my original wheels which led me to think that they couldn't be that difficult to make - for someone with the necessary skills and equipment.
A bit of research led me to the following guide from Mr Laidler (which he is clearly too modest to mention here

) :
viewtopic.php?f=31&t=21090
I shall certainly be looking into this. Edit - reading this again I get the impression the OP may have made some of these centres already, hence this thread?

But hopefully the link is of interest in any event.....