Hey bigbazoo, I have fitted two of these to my yak. However I was able to use a nut and bolt (plus big washers) to fit mine off.........however, one of them is only fixed by two screws as I made the fatal mistake of misjudging (buy about 3cm's) where it was, I tried the hardware shops for rivet style and anchor systems, but am not willing to drill a hole big enough to accomodate them (at least 5mm in diameter) only because the locking off sections in my opinion are not suitable......for the time being I have inserted twho botls with heaps of silicone and it's stuck pretty tight, I can put pressure on the holder and seems okay, but I will be carefull not to target big fish from that location anyway......
I would suggest finding another location if possible, as I feel correct mounting of these is pretty important.
However, if anyone else has a solution, I need to hear it too!