trad ganger dick wightman's site has great tutorials on installing the connexion hinge. he's done it more than once and has paved the wave for easier installations by noting the pitfalls he encountered. thank you, dick!!!
the basic installation concept is ...
cut/grind/sand a 7/8" 'groove' on the bow's back at the centerline. this is where the hinge recesses and requires about 1/32" or so relief all around to allow the hinge male and female parts to best, er, mate. this groove needs to be cleaned up and sealed before moving forward - i'll use multiple coats of thin cya.
the hinge is laid down in position, aligned, double stick taped down securely, marked and drilled (5/32") for the 6 hinge titanium screws. the 5/32" holes are slightly chamfered, and the hinge is laid back on, and screwed down firmly. the bow is still in one piece and the hinge is never ever removed (thanx dick!!), and would be best to glue in the screws with slow set epoxy.
there are any number of ways to cut the bow in half. i think the safest is the way dick did it - clamped in a modified miter box and cut with a really good miter or japanese draw blade saw. a thin piece of metal, perhaps a piece of stainless from a feeler gauge, is rounded bent and forced between the riser and the rounded hinge. tape around the riser completely before cutting, too.
after the bow is cut in half, one or both riser cut surfaces will need to be thickened with micarta or thin leather to take up the space of the wood lost during the cutting.
as to whether the shelf and handle are shaped prior to the hinge installation, i'm unsure. i know it's been done both ways. need to think about that some more ... and query dick!
then on to the final sanding and finishing.
tooling - though it could be done with hand tools for the very most part (no electrics at all), cutting that 7/8" hinge groove will be something i'll tackle with a spindle sander, for accuracy.
looking forward to whacking me a tembo in half. like the houdini saw-the-lady-in-half trick, i hope mine will go back together again like brandy new. :D