Before Queen recorded at Trident John used a Rickenbacker 4001. Theoretically the album version of "The Night Comes Down" should feature this instrument.
Agree or disagree?
yes, I have seen that, but you wrote that both P-bass and Rick were used for TNCD: link
I don't want to say something stupid, but I doubt they recorded two basses. The sound on the recording is quite flat. It would not be really typical for Queen in the early 1970s to record the bass twice. Of course I might be wrong.