Please, which of these Screwpull models is best?

Dan, you can replace just the screw. It’s still more than $12, but less than a new screwpull.

http://www.amazon.com/Screwpull-Creuset-Lever-Replacement-Screws/dp/B000HLNSX8/ref=pd_sim_sbs_k_2

Michael

For the toughest corks, that primitive worm will allow you to engage the cork (or cork remnant) so it doesn’t get pushed into the bottle when you use the Ah-So (with the worm angled under it). My understanding is that the much-heralded Durand essentially puts these two pieces together to make it less of a challenge. If one is looking for less of a challenge.
Charles