Hi. I'd like to ask if have you ever considered creating a C64 reloaded "Mini" version.
If the requirement of keeping the C64 case compatibility could be dropped, maybe the C64R could be redesigned as a smaller motherboard where the chips could be located. in a more efficient way. Only the joysticks, cassette and serial ports could be fitted as standard, and make the user and cartridge ports an expansion option, that could be left in the board as pins, where the user could fit a IDE-like connector to the physical port, available separately as an option. Of course, the audio/video option should be there, and the keyboard could be provided by the user with the use of a PS2 or USB keyboard, having the motherboard the necessary connector.
The users could then create their own custom cases, or you sell one as an option, matching the colors of the original models.
Thanks for reading.