Bob,...
It is not a teardrop antique fan....it is a typical 17-18" 6 blade
'flex fan', aftermarket.....it had slightly curved, flexible, rectangular blades mounted to a black anododized frame....however the shroud scenario you mention is far from my current setup...
the distance from blade to radiator is apprx 2.5-3". The distance from blade tip to shroud is apprx 4-5 inch. The amount of coverage of blade from shroud is about right,...but the shroud itself covers only about 80% of the radiator and is not flush to it....there is a 1/2 gap down the left side......

All this will be rectified on monday with the arrival of the proper shroud from Griffin for my radiator.....

I would assume the mechanical fan alone should be sufficient at idel to pull a towel towards the grill (mine does not at all). Ofcourse, with the electric fan on it will suck a 4lb beach towel to the grill and hold it there :-)......(still rising heat though :-(