Does anyone know the diameter of that spanner type of lock nut (if it has a tabbed eared and a shaft keyed washer under it) or plain retaining nut by chance?

I maybe doing this job myself in the near future on several cars with immense mileage on the struts.
Two of my cars still have their originals! A third I am not sure about?

Also I read that an offset deep hand wrench can be had at a Harbor Freight to remove the top nut if one does not have an deep socket and impact driver.
Is this so? What size does it have to be for either?

Thanks
Phil