From the picture that tool is good for when the supply lines are disconnected, initial install, etc. I can but don't want to disconnect the supply lines, more tight tolerances. This is a 'tighten up the nut to setp the value stem from moving around on the cabinet' job.
The other suggestion to replace with replace with proper basin nuts is a good suggestion. However it means I still have to loosen the tight nuts, only one loose nut prompted this whole project, and disconnect and reconnect the supply lines. All with that tight clearance that is the root cause of all this.
A trip to Sears tomorrow and I may snag some helpful hand tools.
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