"using self-adhesive pads and cable-ties to keep the toroids in place."

Many construction projects in hobbyist magazines nowadays use plastic cable ties - the locking type - thru appropriate holes in the PCB to lock the toroids (and many other similar components, chokes, small power transformers, etc) down solidly to the PCB - NO STICKY PADS!. You can also tie things to the case - but it's preferable if the ties don't actually come outside - that way they can't be damaged and let loose heavy bits to bounce around inside - especially if they have uninsulated wiring!

One particular project not only had a choke tied down this way, but also used a tie placed on the ferrite core in such a way as to ensure a permanent air-gap, so the ferrite core didn't saturate when the ferrite core was closed with another cable tie.