IMO you guys would be better waiting for someone to make a third party one. Will likely cost much less, potentially be better (the bat signal can certainly be improved), and won't come with attendant parts issues (could use a pinduino or such like to control it).

If the Premiums finally begin to sell in good numbers when code gets close to being finished, it's simply a matter of time before someone does it.

A high resolution 3D print, then spray painted would be fine.

Regarding moulding, I don't think that's so much a design or engineering issue as one of the initial sunk cost and then potentially unknown demand.

But if BM'66 does begin selling well once code is 'finished' (initial feature completion), then the standard topper is so expensive and so undesired, and the (S)LE topper even more expensive, much more desirable, rare and potentially unreliable that I suspect there would be plenty of scope for sales of a third party recreation in the $325-475 range.

Other toppers with moulds have been produced already. Habeboo 's JP one, notably.

Re: printing of the images, not really if they're original art, or digitally altered to an extent where they're considered original. If they're just straight copied licensed material, then yes a potential problem.

Re: control of lighting, perhaps you won't get an exact replica of the function / triggers of the (S)LE one, but you could still get a decent, well staged light show with an Arduino or whatever.