Still not found it yet ?
It's an odd looking fly but excellent shots. The colours in those wings are very nice and you're right, the head really does resemble a bats.
I'm still asking around, yeah....
He is indeed Peter.
After some research, it may be Orthocladiinae (Chrionomidae) which basically means, it's a midge.
I thought that - and someone else suggested the Bibio, but the Diptera specialist made the ID (professor type people I think they are, lol)... and I have seen St Marks flies before and they were bigger than the midge I photographed.
Ta for the option though Bod.
We should name it "Bilboia Aprilus Bagginses"