There is a conversion link made to connect prewar box couplers with postwar knuckles. It has been a while since I have seen one. It locks onto the prewar coupler spike and has a knob at the other end that a postwar knuckle will mate with. The only problem, besides finding one, is coupler height. I think the box coupler on the back of your 2226W tender may be too high to mate with the postwar knuckle. A better solution is to make one of your postwar cars a transition car, by mounting a high-step prewar box coupler/truck on one end. This transition car can allow you to run any postwar cars with your 226E / 2226W. I can send you the necessary truck/coupler if you want to try this. It is best that this transition car be one of your heavier cars such as a diecast flatcar, or some weight can be added inside a 6454 type boxcar. You can then pull long trains with your 226E. Let me know. J