We can preserve their function, but the physical experience of using them requires the ability to produce a physical approximation. I can say the C64 Maxi is a low-cost and pretty good approximation of both a C64 and a VIC20 computer. I only wish it could also be a C16 and a Plus/4.
I agree, recreating them physically would be just as important. I'm university I used the HP48 calculator. There's emulators for it, but it's not the same as holding the old calculator in my hands, the tactile feel of the buttons, looking at the reflective dot matrix screen that would flicker under the fluorescent lights.
