Looking for a lead for an oversize rim, please help.

[60s Merc]

Hi guys I am looking for a Penta style alloy for a 1972 Mercedes, the rim needs to 16” X 11J, yes! 11 inches wide. Done usual searches but nothing. Plenty of 8J and some 9J. I’d be ok with a split rim or a purpose made monoblock. Have any of you guys gone down this route?

Many thanks.
Mark.