Just a short notice in case somebody is still reading is - all required parts, except for the fin is there. The easiest way to fix it is to buy the Heller kit and use the fin from that one. Some minor surgery is required to add the hidden join "rectangle" at the bottom using styrene sheets and rescribing the panel lines (really easy on the fin). You need to figure out what goes where and omit the parts not needed for the SH, AJ or SF versions, such as to use the right instrument panel, canard wing, body ring and pylons and avoid attaching the fourth aileron actuator and gun pod.
The added bonus is that you can then use the remaining parts of the Heller kit to build the SK37 or SK37E (which definitely cannot be built from the Tarangus). Just some decals are needed and possibly some resin pods.