The bits that do look like bearing material don't to me look exactly like the bits you showed in another photo, or is it just that these bits have now been photoed better?
You haven't mentioned it, but were all the big ends whole?
Anway, looks like you've got to the bottom of it in more ways than one. Crank regrind at worst and bearing replacement, not the end of the world but very labour intensive.
And I REALLY wouldn't fancy doing it under the engine. Mind you, now you are where you are, it should be possible to do as mentioned above, disconnect all the big ends shove them out of the way then turn the crank to examine it for damage, especially as you know where the damage is likely to be, but you'll either have to reconnect the sprockets and time the cam or remove the head, unless you manage to clear the crank with the big ends without contacting the piston head with any valves.
If you are unbelieveably lucky, and find the crank doesn't need a regrind, about a (.001% chance), then you could just reshell the whole lot and breathe an enormous sigh of relief although reshelling a crank in situ is not the easiest of things to do. (I once knew a bloke who did this with every vehicle he ever bought, in situ, another nutter I suppose!)
The very best of luck mate!