If only we knew which calculator tggzzz has acquired and might be planning to tear down...
Getting it into position for use takes ~30s. Complete teardown another 30s, reassembly another 60s (a little longer to avoid damage). I tore it down while still in the auction house
Cleaning: I'm trying to find a way to that safely, but accept it would probably be unwise to try.
I've seen pictures of some devices up for auction where the surface looks like a RIFA in dangerous condition. In such cases, I cannot think of any solid or liquid (or gas!) that could be used without ruining it. Even so, such devices are almost certainly usable. You can get reproduction instruction books on fleabay for £10 (no, not from ArtekMedia!)
Auction price? I've seen estimates from <100 to >2000 "pesos" (i.e. given that range, the currency is unimportant). The 2000pesos one looks like it was produced maybe 30% into the production run. Mine was about 70% into the production run.
There are
two on display in TNMoC; they inspired me to obtain mine
Couldn't find room (or money for electricity!) for their Elliott 803, Witch, ICL 2906, though.
Final hint for now... Two dimensions are often quoted, but I think the larger is a cheat. Even so, the smaller quoted dimension is
far larger than anything mentioned by anybody in this thread