I'm surprised you didn't take apart and lube the Rabbit as a speed Rabbit to get a 50% bump in the price
Nah, I only do that when it makes sense. And this puzzle is easy to twist already.
Btw, I'm not sure improving rare puzzles always increases the price. My speed domino got 82 GBP but soon afterwards an unimproved one (though with different mechanism, I think, not spindle but groove) got 87 GBP. Improving puzzles might make some people more interested but might also scare away collectors who'd rather get a 'virgin' puzzle. I usually don't alter mint collectibles (unless they're really bad to play with), since they're something special already, but puzzles which are already used and can be improved, I need to do so