Great photos, sorry for late posts I've been away. I've not done a teardown yet as I'm still in functional testing.
Readers should be aware the 3K10B, as well as many PD HV power supplies discussed on eevblog, are earth-ground referenced and non-floating at their outputs. The chassis is not double insulated so take the usual lethal voltage precautions very carefully.
The SHV connectors provide much added safety with kV supplies that are earth ground referenced. Should the cable fail in your hand [other than being grossed cut in half], it will either short the PSU [e.g. failure of the inner core insulation] or will only expose the ground cable braid [e.g. failure of external cable insulation]. The SHV connectors bury the hot lead inside the connector, and the ground connection is made first before the hot lead is connected.
I read that some users have modded HV supplies and replaced the SHV with banana jacks. Although ETL rated commercial DMM probes are tested up to 10kV, you loose the safety of the SHV system and many non-branded banana jacks are not rated to work at the voltages HV PSU operate. If you buy branded kV banana jacks, it can cost as much as SHV connectors. The SHV connectors on the Power Designs supplies are often US made NIST quality, and today run between $10 [branded used or surplus] -$ 70 [new, premium distributor] each. Unless you are careful with sourcing a replacement, its very likely China-grade of unknown quality and specification.
If you buy China grade SHV connector or assembled cable, all you need do is your own dielectric test as it should be 5kV rated and for the 3K10B, the maximum ouput is 3kV which is lower that the rated breakdown of SHV.
That said, there are not many SHV vendors on Ebay and only one in the USA, were connectors run at $6, new, versus $20 new say from Digikey. SHV cables are rarely off the shelf, but are made to order.
With the 3K10B you will be rewarded with some diligence.
At 24 hours, I get 1.5 ppm stability at 700V DC.
At 1 hour, I get over 1ppb stability at 700V DC.
Its not just rock stable but linear from 0.1V DC to 3kV DC, continuously, absolutely amazing quality.
Maximum output at 3kV is ~ 60W, i.e., 20mA.