N
nicebutdim
Just a thought, if you can't get the proper tool in to do the job is the enclosure or work just carried out fit for purpose.
A very good customer needs a supply taken from a perfectly good, but badly glanded board. Do you a). refuse the job because you're going to have to chisel a locknut, or b). do the job and live with the fact you had to chisel a locknut in a job which is otherwise perfectly satisfactory?
This customer may account for hundreds of thousands of pounds of your annual turnover and not everything in life is box fresh or perfect.