I began my comparisons of the original puzzle collection with the boxxle 1 & 2, perfect and revenge puzzle collections using Sokoban YASC's duplicate finder. I have gotten SokoDup to run also, so I have included it in my comparisons also. Then I compared the results of both to each other. What follows is what was found, and what was not, by both programs. I have included the notes I placed at the beginning of the file I have attached to this post for your perusal. Because the output of SokoDup was easier to manipulate for this purpose, I chose to use it instead of the output from YASC duplicate finder. I will make that file available to anyone who requests it.
To make this all easier to understand, I have included a file that displays all of the duplicates found for each puzzle that has duplicates. It is loadable into the sokoban engine of your choice, as it is in standard sokoban level file text format. It uses the Sokoban YASC variant of this file format and originally had the .sok file name extension. I renamed it Duplicates.txt so I could upload it here. The puzzles it contains are not intended to be played. This merely makes it easier to grasp by displaying it the way puzzles are displayed in these game engines. It contains the 34 original puzzles that have duplicates.
I used the tribute file (Sokoban_Original_Puzzles_Tribute.txt) instead of the XSokoban file (Original.txt) because the tribute file contains all of the variants found in all 3 of the original games by Spectrum Holobyte and the original game by Spectral Associates, resulting in 64 puzzles instead of 50.
I shortened the name of the tribute file so I would not have to type such a long name into the command line. I moved the totals to the top so you wouldn't need to scroll to the bottom of the list to see them. Also included are corrected totals after accounting for all the duplicates missed by SokoDup.
Note that SokoDup and YASC Duplicate finder both missed the exact same duplicates.
I separated the unique entries found by SokoDup from the duplicate entries for easier study. Where a duplicate was identified as unique I put the original level number and title of that puzzle to the right of the entry. Where a duplicate was skipped in the duplicates section, I placed boundaries around the entry with notes to the right for easier study.
I had to wrap the lines to make this fit in the post. Using code tags to get a mono-space font caused the right side to go beyond the right margin of the post.
The notes may be easier to read and study in the file.