There are a good few people who have retrofitted rails or fitted aftermarket rails, and the challenges are common:
- Sourcing and fitting rails - see this thread: https://www.t6forum.com/threads/fitting-caravelle-seat-rails.1472/
- Sourcing and lugging seats into position.
- Raising the floor height to match - see this thread: https://www.t6forum.com/threads/guide-raising-the-floor-height-to-match-oem-rails.23889/
- Sourcing and fitting a floor, particularly as two/three piece floors are susceptible to flex when on top of a raised floor - see this thread: https://www.t6forum.com/threads/ply...erior-panels-roof-and-one-piece-floors.19412/
- Finishing the floor, including threshold choices to cab - e.g. https://www.t6forum.com/threads/team-karndean.25831/