For a pure gatecrashing missile delivery system...do you need engines? Your missile transport is slow enough that I assume it's not going to be getting any protection from its mobility.
You could make it delivered to the point inside a hangar, at which point it could have next to no crew quarters. And engineering, if you use military hangars. Kick it out of the bay on top of the point, form up with a jumpship, and crash through right away...
...Relatedly, I'm not sure whether a ship with no engines at all can jump with both types of jump engine or what, seeing as engine type determines required jump drive type. I haven't tugged any stations through points that weren't stabilized so I haven't put that to the test...