I was thinking of a Rube Goldberg method of having a second stalk and some cables but that won't address the matter of the wiper and high beam switches. You might look into getting the column hardware from a LHD car.

The 230E steering wheel is probably big enough that he can keep it steady with his thigh as he reaches over for the stalk... however safe that is.

Sixto
95 S420
87 300SDL