1) Get those wheels straightened out!!! Get the Jeep perpendicular to the fall-line of the hill. If the angle is bad enough for gas to spill out like that (also look into a better cap or getting it put on better), then it's steep enough to induce a roll if you go too far forward or back.
2) Personally, if I couldn't 3 foot it (hand throttles are nice), I would just drop it into 1st and use the starter to move over the crest, or get it started whichever comes first. BTW this isn't for everybody, I have a 97:1 crawl, HD starter and dual batteries.
3) If not able to get some reliable sort of forward motion from the Jeep in question, I would look at the following in order:
A) Strap from vehicle on top already (assuming forward progress is imperative).
B) Winch from vehicle, either self recovery or from top (assuming forward progress is imperative).
C) Depending on what it looks like behind the stuck guy, have him back down (preferably under power so you can use engine braking) and try it again. This time, keep the engine wound up with high RPM's and as much forward momentum as is feasible for the situation.
D) Looks wide enough to get vehicle around him to the top for strap or winch. Is there an FI engine in the house?
'83 CJ-7 nothing original but the tub and axle tubes