All first Gen RSV Mille R and Tuono Factory/Racing that came with Ohlins Forks and rear shock came with forged OZ rims. All Second gen RSVR Factory and Tuono Factory that cam with Both Ohlins fork and Ohlins rear shock also came with forged Aluminum rims. Up until around 2007 the forged second gen rims were made by OZ, after that they were made by Magaltech in Russia, and have a small MGT stamp on them. The RSV4 forged wheels are still made by Magaltech.
The first gen forged rims that came with axial brakes are 5mm narrower at the brake rotor mount (2.5mm each side) than the later rims for bikes with radial brakes. The GenII rear wheel is also about 2.5mm wider on the sprocket side than the Gen I rims. The 2003 RSV Mille R and the first Tuonos that came with radial brakes have the wider front rim and the narrower rear rim. The GenII forged wheel has the stamped Forged along the rim, is a slightly different color and it has a rougher texture than the first gen forged wheel which does not have writing along the rim.

As mentioned earlier base model second gen bikes came with cast OZ look alikes that are heavier than the firsr gen cast five spoke Brembo rims

Most GenII bikes, and all GenII Factory models came with radial brakes. Most Gen I bikes came with axial brakes, except the 2003 Mille R and the Tuono Racing / Factory that came with radial brakes. All GenI base models came with axial brakes. You can not put a radial front wheel on a bike with axial brakes unless you machine 2.5 mm off each side at the brake rotor mount or machine 2.5mm off of each axial brake caliper. It is not the fork width that is different, it is the brake rotor and caliper mounting distance that is different. An accurate statement would be a radial GenII front wheel will fit a Radial GenI bike and a radial GenI front wheel will fit a radial GenII bike with no problem. Some GenI bikes can take a GenII rear wheel depending on the width of the particular rear swing arm on the GenI bike due to production variances, but there will be a small chain misalignment that a number of people have said is inconsequential.
All Gen II RSVR Factory and Tuono Factory bikes came with forged wheels. Only the base models came with the cast wheels.