They are made by Marchesini (not sure) from magnesium as Hades pointed out.
They are exceptionally light weight and I think the stock ones are truly outstanding and top grade and a very expensive OEM component. You would only need to match the size of the rim sizes
FRONT WHEEL|17 x 3.5 in.
REAR WHEEL|17 x 4.5 in.
And then match the inner diameter of the bearing, the outer diameter of the bearing needs to fit the "race" and the width of the hub (with or without spacers) and a sprocket that would fit another rear rim that has a relative close tooth count.
The front may be a little easier, matching the size and a bolt number and pattern to fit the rotors.
Look to Ducati wheels that may fit or be similar in size.
Remember when Victory took over they changed the rear to a 160 from the Brammo 180.