Maybe not quite what you had in mind but: https://www.thefuturewas8bit.com/index.php/c64p

How can you put the original hardware into a case that is half the size? There is no way that the bits inside the case of my recently revived C64 would ever fit into this thing. Even if they cram a "real" SID and VIC etc into it then at least the motherboard and rather a lot of other things have to be rather different.