I'm going to build a model of the 321XLR, and I'm wondering if there are external differences with the standard A321neo.
I think the main differences are internal. No obvious external differences that I'm aware of but, I'm no expert
If you compare it with the Boeing P-8 Poseidon there's no ESM wingtip pods, no external M.A.D. boom but you might want to add an ECM pod on the top of the vertical tail fin. Forward weapons bay and a rear weapons bay to house the sonobouys, underwing weapon pylons, FLIR retractable pod, Chaff dispensers plus all the lumps and bumps for the aerials. Winglets on the tips of the wings.