Here is a comparison gallery of screenshots from both Blue Underground’s new 4K scan of the original camera negative Blu-ray (left) and 88 Films’ 4K scan on Blu-ray as part of their Slasher Classics Collection (right) of The Toolbox Murders. You can right-click and view image in a new tab to do a comparison.
BD Info comparisons
If you like the image on the left (part of the 4K UHD release):
If you like the image on the right: