So to work...
My little compressor quickly gave up the ghost, trying to supply air to JtC's die grinder + cut-off wheel.
Time for plan B... angle grinder with cut-off wheel. Bingo!
(Though being sprayed with molten plastic while holding the shroud as JtC ground away isn't a hobby of mine - I think the phrase "toughen up princess" applies here)
And this is the result...
Factory!
The inner face was relieved to fit it past the power steering pump, water pump, etc. and the outer (radiator side) face was notched to ensure the shroud sat hard up against the radiator core.
Now to make up some brackets to mount it.