The Feemster Famous Vegetable Slicer has been mentioned a couple of times over the life of this thread. The old Feemster may be finest slicer ever. Infinitely variable slice thickness and instantly adjustable without hunting for loose components. They are often praised, but, if you contemplate trying one, you need to know that there is considerable difference between the original carbon steel blades and the current stainless blades. The original carbon steel is frequently found to hold its fine edge for generations. I bought mine used, but still with the original box. That's probably a reasonable way to guess that one was cared for or lightly used. The current stainless blades are not in the same class, and in this kind of work, the edge is everything. Vintage Feemsters appear from time to time on eBay and in garage sales.
The images here are the vintage production model. The box is distinctive. The current model uses a different box graphic, but it's also "vintage" looking, but don't be fooled. And the current model comes with a plastic guide, which is another giveaway.
"Kitchen duty is awarded only to those of manifest excellence..." - The Master, Dogen