Howdy, if you can, I'd suggest heating the bolt heads with an oxy accetylene torch, and heat them to the point where they're just starting to glow red. This will allow the heads to deform enough to release the pressure of the spring washer, which will also lose it's strength. At this point, there should also be enough heat in the bolt thread to brake the rust hold on the thread. Just be careful of what else the heat may affect in the assembly though. Once the heating has been done, let them cool naturally. Don't be tempted to cool them off with water, as it may crystalise the metal making the bolts very easy to break.
Obviously when it comes time to reassemble, you will need new bolts and spring washers.
On the drive situation, I have a complete and servicable rear axle, and two sets of handlebar controls if you're interested. Send me a PM if so. Cheers.
