Joel Metz illustrated his problems with wonderful photos, and thanks!
For the first problem, clearly it wants a different, single cable, derailleur in its present configuration. Looking hard at it, unless you are sure that the paint is original, I'd suspect that the cable stop was a later addition to accomodate "modern" derailleurs, maybe in the 1960s.
For the second problem, removing a SA juvenile single speed FW, I see several alternatives: (1) If it is working ok, postpone the substituton of the TDC FW, rationalizing it as keeping it more nearly original. (2) Are the SA and TDC both the same diameter? Particularly with continental stuff, I've mostly seen threading that was a lot smaller diameter than 1.37." Do check that they are the same... If they are, I have a pair of wild, home-made FW removers. Someone took a strip of 1/8" thick by 1" steel plate, cut an appropriate length, and drilled it in the center to let the axle pass through. Then he bent the ends over, leaving a flat-bottomed U shape, and ground the ends to match the notches in the FW. If anyone is real interested, I'll take a picture and send it to you offline.
harvey sachs McLean VA
problem the first:
the rear dropouts/chainstay of my 1949 jack taylor tourist, in the process of being built up (slow process), with a simplex type juy touriste rear derailleur, look like this:
http://www.blackbirdsf.org/
as you can see, the path that the derailleur cable would take to enter the rear derailleur places it *forward* of the cable stop! the only present solution would be to loop the cable from the stop up, forward, and over itself to reach the derailleur. clearly, this is Not Right. so, it looks like im ruling out the simplex juy touriste.
i am, however, looking for thoughts as to what kind of rear derailleur this may well have been set up with! would i perhaps be better off looking at a single-cable cyclo randonneur type? the cable routing all points to a single-cable setup. theres a somewhat kludged hook for the external return spring, but its way forward, under the bottom bracket, which is much longer than the standard return springs for either the cyclo or the simplex...
problem the second:
the rear wheel of my jack taylor bambino 16" wheel kids bike has an odd "freewheel", which actually seems to be just a cog sandwiched between two spacers, with a simple rachet mechanism in there somewhere. ive got a nicer, td cross kids bike freewheel id like to use instead, but this one refuses to budge. anyone seen these before? sturmey-archer made, appears to be thread-on...
http://www.blackbirdsf.org/
thanks for any help!