Locking lug nut

[Kurt in NJ]

The square washer looks similar to one used with the generator nut ---on my 46 it came with the nut and lock, it was keyed the same as the trunk lock, there was no washer

The 36 conv sedan has a different "nut", the head looks like the nut in the picture, but it has a stud ---about 3/8 that screws into the trunk floor

I have found the nuts in junk boxes at flea markets like Hershey for 1$, there are several versions, and some other make cars used similar parts