Thanks for the info, guys!
Also, thanks for the link showing an install with the read weight removed. Interesting that it doesn't really address how the installer dealt with the loss of the worm cover, as the worm cover is nicely molded into the underside of the weight. I guess the decoder itself is acting as a (rather crude) worm cover?
What I might do to make things easier is just put a LokPilot in this powered unit and then put a function-only sound decoder from ESU in one or both of the dummy B units. Not perfect, as the lead unit would be silent, but it would be basically the same setup with some popular steam installs (GS-4, for example), where the sound decoder and speaker are in the tender.