Thanks to good friend Simon, I have, in my hot little hands, a used viscous coupling. It might be on its way out, getting aggressive after a long hot drive, but it will be great for me this winter.
Here is a view of the front, the front differential end.
A couple of things to note:
-the punch mark up there on the rim between the circlip ends. It aligns with the casting ridge between that screw port and the rim.
– the paint on the screw ports and on the circlip ends.
Closer shot of the punch mark on the rim
The punch marks and the paint on the circlip must have something to do with registration on end cap for balancing. I doubt they were there to help rebuilders, but rather I am guessing the unit was balanced before filling (there are spot welded balancing tabs on the side of the body) and the marks are there to be sure it went back together balanced.
Here is the other end, the one closest to the propshaft.
Coming soon, the install, and perhaps (if I can get my act together) some sort of bench test of the VC.
shooftie 
#1 by Ed on October 12, 2011 - 9:33 pm
that looks like the biggest snap-ring I have ever seen! Thanks for posting photos.
#2 by albell on October 12, 2011 - 10:08 pm
we’ll see if I can get it off the one currently in the van after I do the swap. Time now to hunt down the O-rings, X-rings, and silicone. ab
#3 by Ed on October 12, 2011 - 10:22 pm
whats the situation with your current VC?
#4 by albell on October 12, 2011 - 10:48 pm
Weak. It does transfer some power for I can feel the difference with propshaft in/out, but not enough to be useful.
With torque wrench on axle nut on front wheel (lifted), I get about 37 ft lbs when I try and turn the wheel. Time component not measured (important omission), but I will measure better when the the diff is on the bench and compare when new VC installed.
ab