Thanks for the responses.
I decide to purchase the Parasound A21+ amplifier due to local audio dealers availability, I didn't want to buy something without hearing it, and I was given a nice dealer demo cost.
I had a Sonic Frontiers Line 1 preamp, and some NOS Mullard E88cc gold pin tubes boxed away in a closet. I don't recall why I stopped using this preamp, but with the NOS tubes I like it better than then the BC21, and it has a remote 😉.
So, with the A21+, I now have enough power to drive the Nautilus 804 speakers (which drop as low as 3 ohms). This enabled me to move away from the rear wall and still have some bass. What I quickly learned is that room acoustics are as important as my gear. Almost 2' feet from rear wall and approx 18" from side walls with approx. 17 degree toe-in, and the speakers came to life - palpable and engaging.
The audio dealer loaned me some Synergistic Research speaker cables and interconnects, and they are way more sonically appealing on my system than the JPS Labs Ultraconductors that I replaced. Seem better in the lower registers, less congested, less harsh, and more balanced.
Based on suggestions from other Audiogon threads, I purchased some used SoundAnchor stands specifically for the Nautilus 804s, and yet another step up in acoustics, and improvement in bass.
I installed a curtain over a 9' span of French doors, and yet another large improvement. The room was apparently super reflective.
So, this story ends for now, and honestly if I didn't do another thing to the system, I am very happy with the really nice sound coming from the system.
Current System: B&W NAUTILUS 804s, Sonic Frontiers Line 1, Parasound A21+ amplifier, BC 23 phono stage, VPI Aries turntable w/ Lyra cartridge, Synergistic Research interconnects and speaker cables, Lecture YBA Integra CD.
Prior System: B&W NAUTILUS 804s, BC 22 Amp, BC 21 preamp, BC 23 phono stage, VPI Aries turntable w/ Lyra cartridge, JPS labs Ultraconductor+ interconnects and speaker cables, Lecture YBA Integra CD.
A quick shout out to Scott Walker Audio, they really took the time helping me out, and I greatly appreciate their advise, expertise, and attentive customer support..