I grinded down the welds smooth inside the swingarm to buy a couple mm's of clearance
Grinding structural welds would make me nervous
According to this, the 160/60-17 is 6.67" "actual" width. That's 169.4mm.
https://www.dunlopmotorcycletires.com/tire-line/sportmax-q3-plus/This guy measured 175mm on a 4.25" rim, so even more exaggerated.
https://www.supermotojunkie.com/threads/actual-tire-width-dot-and-race-slick.145216/post-1636113I'd have rather trawled through specs to find the narrowest 160, or fit a 150.
The front was bolt in
Did you drill and tap the CBR front wheel to 8mm for the CB-1 disc? Or did you find some m6 bolts with 8mm shoulders of the right depth? I'm hoping you've not put 6mm bolts in 8mm disc bolts and called it done.
the rear needed custom spacers machined
You could also make those outside wheel spacers as (longer than usual) captive spacers. They'd go right through the CBR's original 20mm wheel bearings and the cush bearing and spacer to reduce the diameter to fit over a 17mm spindle bolt, and protrude into the central spacer by a few mm from each side to keep that in place. This would only require two turned pieces, and save the trouble of replacing the bearings. As a bonus, it becomes easier to remove and refit the wheel as your spacers aren't always dropping on the floor.
I'm also planning to adapt a Ducati 999 Brembo 4 piston/4 pad axial caliper
I'd also consider a 600rr/929/954/RC51 front caliper. This will fit on to a VTR1000F fork leg with just a tiny bit of grinding on the fork leg. Looks nice and Nissin/Honda is "just right". I have used a caliper adaptor before but they always look kinda ugly. It will need an upgrade to a 1/2" master cylinder to work right.
CBR929 gold rear brake caliper
You may also want to fit a smaller, tidier/sportier rear disc. The 220mm disc from a CBR900 (also used on tons of other Hondas) fits the CB-1 wheel. I'm not sure if there's an easy caliper hanger for a 220mm disc that'll line up to the CB-1 swing arm. For an easier job, the Hornet 900's 240mm disc is a direct fit, but looks more modern.