Umm, errr, Cheers jonboy, that is actually us, different user name :oops:
Nothing like asking for advice :roll:
Muddyjames, we are going to rivet ours to the sills with the biggest rivets we could find, says bolt or rivet on the instructions. We've got all the bolts for the outriggers supplied with the sliders, not sure what size they are, but plenty big enough.