The more I hear about it, the more I think it'd need a drastically different contract to have a chance of succeeding. As 'twas, there were enough technical and coordination problems (between GD and McAir) to ensure a rather problematic development. The basic concept was/is sound but the implementation, from everything I've heard, was not well done.
You could, I imagine, use Anigrand's 1/72 kit as a reference for doing a 1/48 A-12. Of course, much of the radar development was supposed to be covered under A-6F development/evolution and that also came up dead (between problems with P&W's second source building of the F404 and with Boeing's new wing, that's understandable). I should not that it wasn't that the new wing wasn't good, it's just that it was sufficiently different from the original wing to cause fuselage structural problems.