Try MWS in Slough (England!). They list this one for the Z3 1.9 but I don't know about a 2.8. The price for an e-type replica is £200 + VAT.
http://www.mws.co.uk/custom/FitmentG...ke=BM&CarYear=
Sadly, MWS reply is "Wheels at the size you request would have to be made as specials and the cost of these is very high"