3:1 is fine.
If you make the opening of the female part 1mm or so narrower than the width of the male part you don't even need to clamp
![Smiley :)](http://www.primitivearcher.com/smf/Smileys/default/smiley.gif)
If you use any collagen glue then just wait a few minutes for the glue to gel and then clamp away if you need to . The parts will not move.
Another trick on things like this is to use parcel tape. A fe pieces put on under tension back and belly would hold it all in place to allow light clamping.
Another option is to clamp the limb section to a scrap board with clingfilm inbetween. Do the glue-up, fit the parts . Clamp other piece to board and then apply clamps.