I am yet to see a used Silvey for sale. If you have a line on one, I would appreciate the contact info.
As far as I know, a $1K Simington is the only option for a current production square grinder.
An ATOP with a Homelite410 vise is over $300 and the angles are fixed. For a low volume person like myself, I would gladly spend $500 on a square file guide/vise combo that would allow me to play around with the angles, control cutter length, and file depth gauges. I am only after the result and shop space is limited for me so a file guide that can be used with a bench vise is much preferred over a grinder that takes up bench/floor space.
Just FYI, I am not able to see any of the pictures posted in this tread.