Interesting concept, but since a spacedock was never depicted in the original series, how would we know whatever was built for the exhibit would be "accurate" to TOS?
I'm guessing you mean a miniature replicating the one we saw in the first motion picture. And "in story", it seems reasonable that platform was already there when the Big "E" concluded her 5 year mission. But considering it from the perspective of the production crew for the series, that thing is far too detailed for what the effects department could have constructed in the late 60s for television.
I remember a painting that was printed in an early issue of StarLog, some time before TMP debuted. I think it was meant for the aborted "Phase II" project. It depicted the Enterprise still in her "series" configuration floating within a rather different dock. The frame used a series of girders that resembled that "tri-rung" ladder we saw at a corridor intersection. Was that drawn by Matt Jeffereies or Mike Minor? If either of those people, who both worked on the original series, drew that design, I'd say that might "meld" better with the Jefferies/Datun miniature.
Then again, I think some people might not like having the "Gray Lady" partially obscured by a some sort of frame.