...unfortunately a previous owner cut the top of my shroud away to make fan removal easier...
Since this W113 fan shroud seems to be uncommon, in lieu of trying to replace the rare part (which will be costly, if you find one...) have you considered repairing it? If the top was cut off, this should be a relatively fix for any sheet-metal "body man" (understanding it could be a woman).
Armed with some of the good photos here, my guess is it's easier than replacement.