How about this, the Trifoliate Orange?
http://www.google.co.uk/images?hl=en&q=poncirus%20trifoliata&um=1&ie=UTF-8&source=og&sa=N&tab=wi&biw=1584&bih=824
OOPS..just re-read your post, it's not the trifoliate orange that's got hellish thorns! Definatley Quinze, probably Chaenomeles x superba as...