Got the 2-wire cabvling done, the regulator installed, and the internals tidied-up. Answering my own question about consumption and regulator dissipation: with my PSU and the KAB regulator, the PSU output voltage drops to about 32V, so the dissipation is in the 2W range, all good for the LM317P and the huge heat-sink that the chassis constitutes. It's now playing Dire Straits Water of Love, and yes I notice a difference in darkness between now and before, although this is not a real A/B test. It takes out the main source of noise from the turntable chassis and that's the goal, it can only be better. No picture yet as the final case hasn't arrived. I need to figure if I pay Schaeffer (aka Frontpanelexpress) to make me a nice panel with the logo, might makes sense as this turntable will be mine for many more years.
P.S. 3 PCB remaining for interested.