Hm. Do I really? What is "Procedural Service" anyway? It was not in the syllabus when I took ground class some 10 years ago - or I should have forgotten, which is not impossible, not at all
Might well be another UK peculiarity. Oh well. Till proof of the contrary, "Class G" is to me absolutely equal to "non-controlled". But on another occasion I have heard rumours that the UK seems to have controlled aerodromes in non-controlled airspace, too - comprenne qui peut.