Looks like crankcase part number's have changed twice since introduction, (up to #242555 then up to #280583). to get some idea my 2009 Classic's # is 318205. As has already been mentioned one of the changes could be from silver to black, but in any case it would be unwise to go for anything before #280583.
Crankcase pairs are available as replacements, £2300 incl VAT in the UK, probably around €2600 over there. If your bike hasn't done a lot of miles and is otherwise repairable that's the way I'd go - you just don't know what kind of 'can of worms' you will get with a used and older engine.
Edit:
Looking at your images again, the ripped-out part is just the lug for the gear selector shaft which is a slotted actuator on the inside, its obviously just been swiped off pretty cleanly and as there was no actual fixed connection to the parts inside I reckon you might just be lucky. Even more reason to go for new cases imo as its very possible there will be little damage to the internals of the motor.