How much axle space for the cap nuts and chain tugs?
I would first try a standard nut on the axle because often the cap nuts have a nice rounded entry to the threaded area which means the trhead doesn't start for a millimetre or so. From the photo it looks as though you should have enough axle for a standard nut to work.

The next step is to grind off some of the antirotation washer so your nut gets more space. Those washers are made of a nice hard steel so they're hard to file. Much better to use a power tool if you can. If not, get the finest, sharpest file you can. And try very hard to keep the surfaces of the washer parallel - if they're not you are much more likely to strip the nut.

And Neil Finn, the cable attachment shown above is the less problematic of the Shimano 8 speed ones that I've seen, but it's still prone to sticking bits of broken gear cable into your fingertips. Note that hhh has a broken strand and there's no end cap on that cable. Unless it's soldered it will eventually fray and then grabbing hold of it to fit it back into the hub gets ugly.