This is the two-part bracket I came up with for the z-head. The round part will need a hole drilled in the belt cover. There is clearance above and below for the belt. 

Once fitted I find that the scale is now loose. It is not loose in my bracketry, it is the oil-seal ring that it attaches to is only held on with two set screws. These were mounted front and back to minimize wobble for the front mounted depth stop, so I had made new dimples for them and rotated the ring 90 degrees. A little bit of milling and they are all loose. So I am ordering new knurl-grip set screws from McMaster - this time they will be hex head not slot head and I'll install at least 4 of them. De-grease everything and use red Loctite. Maybe some Loctite on the ring itself too or some painters tape under it to make it a tighter fit.... 

These set screws come in a pack of 50, and I'm pretty sure there are several other screws on the machine that could use upgrades - like the ones that hold the acme nuts in place.