I dismantled the net, cut off the broken section (and the opposite side which was also about to break), drilled new holes and reassembled - good as new, although very slightly smaller.
It'll break again - a design flaw drilling a hole at the point of stress. Just needed to test it - a couple of coke bottles waved about in the net in the garden would have done - but where's the fun in that?
So I shot down the river - any excuse! Not much time but confidence is high at the moment - two barbel - a very hard fighting 7lb 5oz and one about 3½lb - repaired net tested and approved!