I made my lash up after reading this thread:
https://www.vintage-radio.net/forum/...ad.php?t=76514
Discharging a capacitor into a coil wound round the magnet is the method used in the RFL-440 remagnetiser, the manual and schematic for which is included in the above thread.
I have in mind to make a modern version of this, I have a box of meaty 440V capacitors and several 300 ish volts transformers. The power rating of the transformer is not an issue as I can just use a series resistor to limit the charge current, it will just take longer to charge.
Care will be needed re safety as it could be lethal. The RFL-440 has a table and hood assembly with interlock as an accessory.
Peter