Mirage IV M, designed for PA58? Or the later version?
Iirc the original design study called for a 20t strike aircraft, 19m length by 12m wingspan, with twin P&W J75 turbojets. Land-based version would have been the Mirage IV C.
Later supposedly a smaller variant was offered as a 16t fighter in 1961/62 or so (with essentially very similar data to Mirage IV A, the "smaller cousin" to the IV C). Whole thing was cancelled with PA58, neither type had prototypes or anything like that built. All a bit shrouded in darkness obviously.