I started disassembly of the 700 to change it over to a 10-speed cassette.  I've lost my cable cutter, but I may not need it, the old ones are still slick.  I "fixed" the upper guide tube.  The idler still spins, but the bearings are rough, so I will order another one.  I removed the cassette from the rear wheel and cleaned and checked it, and found the bearings are rough in it, too.  Back to considering a new wheel.  I put the new cassette on it and weighed it with my hand scale.  It might have lost 20 grams, plus or minus 20.  I gave the frame a sponge bath and washed off a half pound of dirt and sand.  Preliminary reassembly starts tomorrow.

OK, now the frame is clean(er), the parts are buggered with and strewn around the room, and the tools are here (after three trips tom the workshop), it's time to see if I can make this stuff work.  First the idler/ chain plumbing assembly goes on while the trike is tipped over.  Then the wheel assembly.  Next, the new rear derailleur screws onto the hanger with its captive screw.  I checked the hanger bolt and tightened it, as it was loose.  The Lego-esque instructions showed adjustment for the space between the jockey pulley and the small and big cogs, which had to be compromised.   Also, the high and low limit screws can be adjusted approximately.  
Now, if you are contemplating such a project, it's time to mount the trike on your workstand, in order to have everything in the easiest position to work.  HA HA HA HA HA HA HA HA!  You don't have a workstand that will mount a trike, do you?  BikeMart doesn't have a workstand that works for a trike.  If there is one, only Doug could afford it.  But if you don't mind working on the floor, you can mount the trike in your trainer, so it stays in one place, but you can move the rear wheel at will.  
Now mount the base of the shifter.  The shift assembly of the Shimano bar-end has a slotted screw you remove so that the parts drop out onto the floor.  You then access the screw inside the base with a hex key and screw it in to loosen it and pull it out.  The SRAM shifter is held onby a hex recess screw and comes off in one piece.  Its base also tightens with a hex key, but you tighten it by screwing it in.  If you fray the end of the cable at all you won't get it in.  I recommend threading it through the shifter head before attaching it, then through the hole in the base, then into the retracted end of the cable housing before repositioning it.  Then you can pull everything together, with the shifter in the furthest forward position.  The cable threads through the barrel adjuster, around a groove, and under a washer held with a screw.  Fasten it down holding minimal tension on the cable.  The derailleur is in its small cog position, and pulling the shifter back through its detents pulls the cable back and the derailleur pulleys go up the cogs.
(Cont.)