It sounds like your (more or less) just using classes for just namespacing functions and allowing bundles of functions to get brought in?
I'm not sure if that's "the fsharp way" (i suspect it isn't) and maybe I'll look back on it some day and cringe, but it's working pretty well for some of my (admittedly small) side projects I'm tinkering with right now.
In general I use a suave functional styled api on the top, OO-style SOA in the middle, and mostly functional style at the bottom layer, something of an FP-OOP-FP sandwich. I jokingly call it sandwich oriented programming.
I do realize that most web work is really more functional than OOP, but classes do make it very easy to bundle dependencies without adding noise to the implementation/signatures.