Anybody here got a leftover Naim 555PS regulator after upgrade to DR version?

Have you looked into power supplies from Teddy Pardo Audio?  They are MUCH cheaper than Naim.  
 

I sort of worry about what to do when my 555PS DR gives out.  Unfortunately for me, Teddy Pardo does not have a direct replacement for that power supply, but they do offer alternatives for other Naim power supplies.  I have not heard them myself.

The problem is I have an unknown condition CDS3 and I need a mockup PSU to check if the player is worth the trouble. I think I can build something akin to Teddy but would need a simple solution first to check viability of the whole enterprise. getting a "door stop" regulator board with matched proven quality of simple 317/337 regulators is the easiest path. The alternative are Chinese boards with who knows what parts. A person whose opinion i kind of trust indicated that old stale PSU sounds better with CDS3 than DR version. XPS-XPS2  board would work too.