Jeep have stuck the Pioneer tag on most models they've made over the years, with no consistency as to what it denotes. I'm not sure if the SJ was a sub-model or a trim package, the Commanche was the middle trim level (the years it was available), the XJ Pioneer might've been a limited edition (one's just come up for sale here which looks like it's 1/2 Cherokee, 1/2 Wagoneer) but the KJ Pioneer was just a plain old panel van (as my picture shows), which, it seems, was only available in (some?) export markets. So, no back seat or seat belts, a flat floor & although I believe the rear doors are functional they can only be opened from outside &, from memory, have plain, flat door cards.