Thanks for the inspiration! My Lionel 18" aluminum Hiawatha arrived several weeks ago and I was dismayed by the huge gaps between the diaphragms. The cars are a mixed blessing: The carbodies are beautiful - gorgeous - fantastic, they're even equipped with LED lighting; the trucks are sprung and the equalizing bars actually work! The problems are the gaps between cars and the fact that the coach and dining car interiors are wrong, dead wrong - partitions and cabinets are located in mid-window... disgusting. Lionel won't replace the interiors but I'll modify them with my handy Sawzall and fix the gaps using your patented technique.
Not wanting to be restricted to 2 degree curves, I was contemplating mounting Kadees on the Lionel drawbars instead of carbody to engineer greater flexibility. I was measuring both and had concluded that it was doable when I finally hit upon and entered the magic search criteria on the Forum search engine and found your article! I sure felt a whole lot more comfortable about butchering some very expensive equipment knowing that you had done it successfully and so successfully - your photos and videos are truly "inspirational".
Instead of grinding off the Lionel rivets, I used a 7/64 drill bit to drill them out which made a very neat job of it. Having experimented with increasingly larger drill bits, I found that the 7/64 is the size of the existing hole and also made a good fit for a 4-40 machine screw to hold the Kadee in place. After removing the claw and associated stuff, I cut the drawbar off just past the first hole and fitted the draft gear for a Kadee 742 in the newly vacated space, lining up the Kadee center hole with the Lionel second hole. Drilling out the center hole in the draft gear to fit the 4-40 screw removes the plastic bushing but the 4-40 machine screw is the same size and serves the same purpose to hold drawbar, spring and lid in place.
The knuckle-side of the Lionel drawbar needed to be removed to match the inboard cut line on the off-side, and the off-side needed to have some material removed, too, to admit the Kadee draft gear. However, the Dremel tool made short work of both. I had hoped to use Kadee 740 couplers but the degree to which the draft gear must be modified precluded the use of the use of metal. It took all of about three minutes to filed down the sides of the plastic Kadee draft gear to get a nice, snug fit.
By cutting off the Lionel drawbar just inboard of the "first hole", the lip on the top of the Kadee draft gear fits perfectly against the fresh cut while the center hole on the Kadee draft gear aligns perfectly with the "second hole" on the Lionel drawbar, and a 3/8" 4-40 machine screw is the perfect length to accommodate installation of a nut. Since the floor/frame of the cars is indented upward at the end of each car, there is plenty of clearance for the nut atop the Lionel drawbar without any fitting, filing or fussing. The couplers match up with the Kadee coupler gauge perfectly without any adjustment whatsoever.
I've completed my first car, the Skytop Obs, and all measurements indicate that the diaphragms will merely "kiss" when a coupling is made and that draft gear spring tension will have the striker plates barely touching on tangent track. It'll be interesting to see what degree of curve they can handle and, just like the real thing, I'll have to wind on a good handbrake to ensure a good, solid "buff" for coupling and uncoupling.
Following surgery to rearrange the interior of a coach, a second car should be completed early this week and I'll post photos of the results. Thanks, again!