unfortunately, the voltage is a bit too high- it puts out ~520VDC
(after a 3-pole filter 10uF/10H/10uF with 40kOhm bleeder
resistor). I am looking for some ways to bring this down to the
voltage I need.


As a first, simple, experiment disconnect the 10uF nearest the rectifier and
reconnect it in parallel with the other 10uF. Then see what DC voltages you
get when drawing currents between 120 and 230mA. If it is near enough to the
370v you require, then add suitable resistors to deliver the other supply
voltages and currents you've specified and you've got what you need.