Checking out the new arm and deciding on the old one

So tonight I thought I'd go down and remove the zxr swing arm and temp mount up the Aprilia 2008 arm.
Removing the zxr arm was easy enough , as was fitting the 20 mm spindle of the Aprilia arm in the 25mm spindle holes of the kawasaki's.

Whats really surprising is the fact that despite the size of the Aprilia arm, it is in fact lighter.I checked the length and they are very similar in length, almost exactly the same.
Now then, back to the questions of fitting the arm. As I checked them back to back it's fairly obvious there is a difference in the rocker linkage systems, however the actual pivots on both swingers are almost in the same place and at the same height, which helps. The only worry is in the length of the sleeves holding the parts together. This is where an outrigger may help.

Heres a pic from another angle. The question is, if the triangular setup used by Aprilia is a necessity to strengthen up this area. And the other question is if this would work using a kawasaki sleeve without an outrigger. I'd feel safer knowing the answers...

To make the arm fit will require the rotor to be turned down to 220mm for the Brembo rear caliper.
Even more weight removed. I'll be staying with the standard Kawasaki wheels for the moment due to the costs of getting lighter wheels, although it may be worth while looking for more modern street wheels as they'll be lighter for a start.

Now , finally with the ZXR arm off I could check out the damage caused by the crash.
Read a few lines on forums and the real question is if it's safe to weld this back (TIG) or time to get a spare one. Haven't really decided.

As has been the case after the crash, small question marks turn to serious question marks! The weld has held but ripped the swinger open like a can opener.