YES.
I fitted XS rear WM3 rims on one of my CB360's which are pretty much same hubs as CB400f
Modified CB360 hub with WM3x18" MX rim.
MX rims use larger diameter spokes/nipples so you need washers under nipple heads
Hub after mods and polishing
Modified rear hub with XS 650 rim
The angle of drillings are perfect for CB350 drum front brake but need slight file 'adjustment' for disc hub
Use a chainsaw file, only takes a couple of mins for the entire rim
I have another pair of XS 650 rims I'm going to fit to disc hub, it's a crazy amount of work to polish old rims though
I very nearly just bought the WM2 for the front, but, checked my paypal account first and cancelled