In late Victorian UK and the US they had electric arc lights that were too bright to look at and which many people complained about. Sometimes they were placed very high up, so as to cast as much illumination as possible over a wide area. In the heart of London this might have been a problem starting in the 1890s or so, I suppose. I don't know for sure how pervasive these lights were in London, but they did have them.
However, I agree that for the most part, industrial pollution would be a worse problem for sky visibility than light pollution, because gas lamps just don't cause as much light pollution, and arc lights certainly weren't on every street corner.
I would guesstimate that around 1850 the smog problem wouldn't be too bad except around some few big factory towns, but by 1880 or so any sizeable town that had an industrial economy would have a serious problem. Rural towns with no heavy industry might fare better, but at that point there was a lot of industrial build-up throughout the country, and even a completely bucolic little village might suffer some hazy skies from other industrial towns nearby.
But there must still have been some places -- Cornwall, some parts of coastal Wales, the more rugged and distant parts of Scotland, and others -- which enjoyed clear dark night skies.
Of course, even with no smog and no lights, the weather in most of Great Britain is such that there won't be all that many perfectly clear night skies in any event.
I was in and out consulting the Jodrell Bank observatory website and working out the bright one near Orion was probably Jupiter. Milky way visible.
