so far what i've done is try to naively replace the burnt out bulb with a similarly sized modern one, after a lot of swearing and fiddling i did manage to replace it but the result is while the flash does fire now, it's extremely dim and doesn't serve its lighting purpose at all
so fast-forward a little, i now know more about xenon flash tubes and how they work, and there are currently two suspects in this case:
- the new lamp i used as replacement expects more than 250V to fire
- the 250V capacitor (a small film one, mind) could be bad