D-76 and Plus-X is an excellent combination, much better than Rodinal and Plus-X in my opinion. Rodinal won't let you exploit the full film speed of Plus-X and doesn't deliver nearly as much shadow detail as D-76. It will punch up the mid-tones at the expense of shadow and highlight details though, making it acceptable if you are working under controlled lighting conditions. The fact that your Plus-X is out of date should be no problem unless it's very, very old, and/or has not been properly stored. The cooler it's been kept, the better your chances are of having a perfectly good piece of film.
Delta 3200, like its American cousin TMax P3200, doesn't age nearly as gracefully. I had some TMax P3200 two years out of date that had been stored in the freezer. When I used it, base fog was high and the film had lost a good bit of its sensitivity. I'd expect Delta 3200 to behave in a similar manner. Having said that, your best shot with this film will again be to use D-76. Rodinal is not a speed enhancing developer. It is especially not good as a push developer, which is exactly what's needed for a super speed film.