Legacy? You know most of the MWDA characters put in appearances in Bonfire of Worlds? Biggest ones missing IIRC would be Danai Centrella-Liao-Centrella-Liao, Yori Kurita and anyone from the Republic.
As for that being a JES missile carrier . . . yup! I was looking at it with Mech-Glasses, but once you suggested a vehicle the length made sense and the treads no longer looked like a weird shoulder set up.