The Shamblo is definitely makes me think of (in terms of the "based on a weapons plan designed by Haman Karn's forces during the first Neo Zeon War") the
AMA-01X Jamru Fin. It even states that it was never fully completed either.
Given the use of Reflector Bits and a Minovsky Craft System too, it more than likely got additional help from Neo Zeon's acquisition of the Psyco Gundam Mark II during ZZ, which was also the same period as the Jamru Fin. (And also more homage too alongside the Kshatriya = Quin Mantha and the Nahel Argama.)
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