Question about the ending

I enjoyed this on the whole – the live nature of it went well, with relatively few slips (great recoveries by the actors) and a reused 1950s script that veered from charmingly dated to still profound after all these years. The central performances were great, even though Quatermass was so much younger than I would have expected, but there was some 'cheating' on the live thing in the form of lengthy prerecorded inserts of overhead cityscapes. Anyway, my question is: How did the now lost original last episode end? I have seen the film and I have read that the TV version had a monster manifested – with primitve special effects involving a rubber-glove puppet – on a model set of the interior of Westminster Abbey, as represented by a blow-up photo of the real thing (we laugh, but no doubt this looked very effective on the 9-inch TV screens of the time). Here, we had the Abbey substituted for Tate Modern, which was fine and allowed for the amusing if superflous addition of the art expert – but how hugely disappointing was the actual denouement? I was gutted! No rubber-glove beastie! No electrification of said monster as in the film! So, was that not in the TV series, then? Instead, Prof Q talked it to death by appealing to it (well, to the empty darkness as it was said to have somehow integrated itself into the walls and was not shown at all) and so drawing out the lingering humanity of the three human astronaut victims. Oh dear me! Was this not the oldest sci-fi cliché in the book even back in the 1950s? Even if not – and fair enough to Kneale if he invented this now well-worn idea – why were 2005 audiences denied a view of the final creature after all the build-up? Did something go wrong that necessitated the ending we got? I know it ran 20 minutes short on the schedule.