Onestopdiyshop.com has a pure orange flavor by Flavor West. I've also seen quite a few orange cream flavors that might work well. I'm way, way over my vaping budget right now, or I'd go ahead and order a few things to try out.
Provided a good orange flavoring could be found, I think Halo's Coolmist would be a great base to start from, with a bit of a good tobacco juice added in. Maybe Halo's Prime 15 or Bella Valente. I haven't tried many tobacco juices though, so someone else can probably give some better suggestions on that end. Maybe a bit of mint as well, since the Halo juice is menthol, with not really any mint to it.
It'd be pretty nice to be able to recreate that flavor, and maybe improve on it a bit. Even though I liked them a lot, they were a bit lacking on the menthol side.