In my day it was not only common to use equalizing resistors across
each diode, but a .01 disc ceramic as well.

12 or 15 years ago, I built a 1KV .5 amp supply and as I recall, used
560K 1/2 watt resistors and .01 uf 1KV caps across each 1N4007. And a
"soft-start" relay in the primary of the HV transformer.

John