I did one like that but it was very low power......it was because my PCB was connected to a 50khz power bus and had to slowly charge a battery from it...the mech eng guys fitted up the core halves for me.......they used a special sponge with the correct youngs modulus to pressure the core halves together without kind of slamming them....the core was kind of glued into the enclosure on the sponge, and the mech guys made it kind of like a lid, so that i closed the core halves together, and the sponge made the core halves pressured together without damaging the ferrite.......i shoved the windings in the pcb, and sufficient slotting to enable the core halve protrusions to go through the pcb, and that was it...sorry if not too helpful.