I found taking a Polaroid 150 apart much more difficult than an Agfa Ventura 69 (see http://uptowngallery.org/Murray/AgfaFilet/ ).

I was able to get access to the bellows on the Agfa, but my goal wasn't to put it back together. It wasn't on the Polaroid either, however, which was built like a tank (and the Agfa being more like a VW).

Someone at Polaroid must have planned for serviceability on those cameras, but they seem pretty impenetrable to me, reversability-wise.