i would agree . . if you look at your two exsamples , the side plate around the lock bolt is the same size as the bolt head ,, right ,,, so what i would do is reduce the size of the plate around the bolt . which by the photo of your plate on the stock , it should give you another 3/32 to 1/8. which will give you more then enough clearance when you rasp or chisel the stock shape down to the mortise
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