Ok cheers guys. Just to update, I've tried tightening it all up, and last night was the final straw, there is just not enough room for my shoulders, and I find that it makes the hammock feel really small too. I've adjusted it, moved it, shock corded it, all kinds of things. I've concluded that it's just not wide enough for me.
And its not different widths at each end, it's exactly the same (I just measured it), it's also symetrical in shape terms ie not wider around the shoulders.
So I think I may have to have one made which is a good 8 inches wider. Thanks for all the advice, and I may well be putting it on the for sale board in the not too distant future which is a shame because it's a great product and I've looked after it, I just don't think it's right for me.