I really like that refit design. Here Shaw has done something similar, but working from the refit backwards, keeping a refit width saucer and retconning it back to TOS
A cross between that and yours would be nice. The actual TOS secondary hul is rather flat on the bottom, allowing you to actually stand the diamond select art asylum TOS down even without a stand if carefully done.
Your TOS/refit sec hull is the most fluid while still keeping the TOS lines
Similar in feel though pre-TOS