Larry,
On the couplers for the Connie, you can replace the tender coupler with a Micro-Trains 2004. (Available assembled or unassembled.) To do this, you simply "pop" the draft box of the existing coupler off, remove the coupler and spring (assuming they didn't pop off to neverland) and then, depending on how picky you are, you can either simply shave down the nubs flush to the mounting pad that held on the old draft box, or shave the entire coupler mounting pad down flush to the level of the surrounding surface. The difference between the two is that if you don't shave the mounting pad down all the way, the coupler will sit a little bit lower than it should.
Either way, once you have the surface prepared, drill and tap a hole for a 00-90 screw into the mounting pad so that the edge of the new coupler box is flush to the back edge of the tender. Set coupler onto pad, insert tiny 00-90 screw, and voila, done.
Its actually simpler than it sounds, I have already done 4, and have 2 more to do. If you are going to go the MT route, I suggest that you simply get their
N Scale Coupler Starter Kit which has all the drills, taps, jigs, and such that you'll need for doing MT couplers. For the front coupler, you can either replace the coupler with a 1015?, or use a Z scale coupler, or simply wait until you're comfortable with changing it. IIRC, it has a dummy knuckle that will couple, albeit not easily, so unless you need to doublehead locos or back the thing up pulling a train by the nose, its not a big deal.