After having arms slowly deflect up on me for my upgrade on my Replicator 2 I began to look for a more permanent solution. There are several different types of aluminum and ABS models out there. I took my MK8 design, added the pin and tab found on Whpthomas's version, and made a few modifications to get it printable at Shapeways in stainless steel. I know there were possible tolerance issues considering Shapeways gives a very large tolerance. The part I received measured very close (within .15mm), If you have this made, bear in mind the possible tolerance issue.
This thing is licensed under creative commons, and all original files can be downloaded free. This model has been derived from these models:
Whosawhatsis' model: http://www.thingiverse.com/thing:15718 Emmetts' model: http://www.thingiverse.com/thing:28241
My model: http://www.thingiverse.com/thing:35810
Whpthomas's model: http://www.thingiverse.com/thing:42250
The current file and additional files to make it work are located on Thingiverse as item 86162.