Euan
The LDO has fairly plain wings as a dun, not much veining, but generally most spinners have clear glassy wings.
The easy identifying features for most upwings are the small hindwings, you can just make them out on your photo and they look like LDO ones.
The body colour with the Light bands is also an LDO identifyer.
As spinners, flies often travel a quite a long way on the wind so its not unusual to find them all over. We had some march browns in the hangar this year, so go figure
Sandy