Hi M Fisher, I was there last week, it was hard work, BUT it is normally a good fishery! The weather was abysmall and the rain and wind a night mare.
There were three of us fishing in our group, we tried Daddies, had one and lost it

lots of follows, we tried buzzers, nymphs etc, little interest couple of little pulls

all on floating lines, in the end I took a nice "bow" of about 3 and a half on a damsel fished jerky, Chitlins and Hodge took 2 on an Orange damsel type lure.
There was one fella there who took four in the day on an orange lure/floating line set up.
It is normally a cracking Dry water, daddies and Clinks go well, or the good old Damsel goes well OR nymphs/black buzzers, on a floating line fished almost static work well. My favorite areas are all of the top end or the bottom corner opposite the lodge depending on the wind, if you can and the wind allows fish from the only slot cut in the reeds to the right hand bay from the lodge. Keep moving too, follow around and fish to where they are, don't stay in one placeand be sure to take your waders, I am sure you will have a good day, it is a stunning fishery with a depth of about 10/12 feet and clear water and a pleasure just to be there.
Google Lechlade Trout and you will get the new website with all the tactics etc on it.
Hope this helps.