When it was first released by Frog in the late 1960's, one of their last kits, it was more than acceptable, but of course, people expect a lot more today. Remembering the frog kit is a MR3, similar in general appearance to the AEW2 posted above, it can be made into a nice model, with a bit of work, and some scratch-built interior detailing. The internal parts provided in the kit were typical of the period - acceptable, but basic.
To build the AEW2 as shown means a conversion from tricycle to tail wheel landing gear, including modification or replacement of the main gear legs, the addition of the radome and a few details here and there. Unless there is still an aftermarket convesion kit available, it would mean a lot of scratch-building, and probably a search for a suitable kit which has a similar radome, such as a Gannet or Skyraider, which can be 'donated'.
As mentioned in my previous post, I haven't seen any ads for a Revell Shackleton, so I don't know if it's a re-issue of the Frog kit, or a new AEW2, that is, if there is a kit.
EDIT: I've just looked at the links poasted by Ian, and see that the Revell kt, which I presume is now out of production, is the MR3 version, so almost certainly the old Frog kit. Even if it's a new tooling, which I very much doubt, it will take some work to convert to the AEW2 or MR2.