Re: Sofa Bed With Seat Belts
There are certainly options out there for used (craigslist, junkyard) and new sofa seats (check out discountvantruck online), but I'm not confident that many have the seat belts built into them. My best guess is that often the mounting hardware and/or seat frame is not up to par with what would pass the required safety standards. Perhaps others can chime in on their configurations.
What you most likely will want to do is get a sofa seat and then independently install the seat belts through the body/floor with adequate plate washers or other hardware to prevent the bolts from pulling through the sheet metal. What I have done in the past is mount a piece of unistrut to my floor so that I have some flexibility in seat belt placement - YMMV.
Seat belts are always a touchy subject - good luck!
2009 Express AWD, CCV Top & 50-ish home build. Daily driver/camper/kid hauler