According to Morgan's price list it is not possible. You can order a Plus 4 with alloy wheels and exchange them with steel wheels and hub caps. Someone told me that the steel rims are not available anymore.
An alternative would be to buy a used 4/4 70th anniversary. They often have steel wheels and a more powerful engine than the actual version.

Keep mogging,
Christian


2006 4/4 70th anniversary, 1985 VW 1200 50th anniversary, 1977 Vespa 50 Special, 2003 Vespa PX 200E