One of the problems with OO gauge track would be that the webbing between sleepers will be even more obvious because of the greater distance between sleepers. I've been thinking about how to solve this problem I arrived at the idea of having the sleepers loose on the rails, the track is laid with the sleepers held at the correct distance by a plastic strip in between the rails. This strip should be castellated on the underside to help keep the sleepers apart at the correct distance. Once the track is glued in place, the strip is lifted up before ballasting. The strip should not be too wide as this would cause problems on curves, and not so deep as to risk also being glued down. This would make is easy to change sleeper types and distances between them as wished .