I have bought the Stringfellow adapter. It's very nicely engineered and fits very well. I haven't had a chance to try it though. However, I have attached a post from my local forum, Seabreeze, below:
"So I finally got the 683S and the 450 stabiliser and have had a couple of opportunities to try to it out, attached to my Slingshot mast via the Foilmount adapter.
I bought the Foilmount adapter first, rather hastily, and then realised it shifted the mast position towards the back due to the position of the screws. I then bought the 743 "Stringy" fuselage, which shifts the mast forward compared to the standard Moses 710 or 749 fuselage. Alternatively, I could have got the "Stringy" adapter, which shifts the mast forward and used a standard Moses fuselage, but being a TA, I stuck with the Foilmount adapter. The Foilmount adapter and 743 fuselage (which is really more designed for the 633 wing) is a good combination and works well with my 4'6" Dwarfcraft board.
1st session I could definitely notice a noise when cruising downwind at a pretty decent speed, one I hadn't heard before with the hoverglide. I wouldn't quite describe it as a humming, more like the noise a motor or pump does when a bearing is on its way out. Not super annoying tbh and not audible going upwind or normal cruising.
After that session I decided to hack into the adapter to smooth the edges out, make it more hydrodynamic-looking, what I had always intended to do. I had been thinking of how to do it for a little while, and hadn't really settled on a shape, but in the end I just grabbed the b@stard (the file) and ripped into it, conscious of not shaving too much meat off the little piece of aluminium that was the only thing holding my new awesome foil onto my cheap mast. Bit of black metal primer afterward.
2nd session heading downwind quite fast, performance-wise seemed the same as before, but couldn't hear the noise, just the gentle hissing of the mast. Pretty happy with this outcome.
Comparing the 683S to the hoverglide, I am finding the 683S way better, probably not unsurprising. One unexpected plus though was the weight. The Moses wings and 743 fuselage weigh about 1.6kg compared to the equivalent hoverglide setup, which is 2.7kg. The 1.1kg difference at the end of the 90cm mast makes a HUGE difference and makes everything generally more awesome; from carrying the board, to body dragging and water starts."