My cal 11/12 Monza has white subdial hands too - only the cal 15 has the red one as you say.

I reckon the economy ones are the plain steel cal 15 ones - unfortunately the whole Monza range is seen as the 'economy' version but we now have more evidence to disspel this myth!

I wear mine as much as possible - but only for short periods - keeps excellent time on-wrist

I've seen a few come up for sale with 'battle scars' and there is still black coming through and not steel so I reckon they're more forgiving than PVD coated ones.

Regards
Dave