You've definitely hit the nail on the head there with that mix of lanterns. And I can understand casual replacements of lanterns, but even the mix of concrete columns was crazy with a mix of swan necks with standard and even those were all different to each other..That reminded me about the concrete columns around here. Although sleeved, my road has Stanton 7 concrete columns fitted - and each column is either on a corner or opposite a side road entrance. However, at a later date there has been an 'infill' with a new column at the eastern end of the road added, and large gaps between the Stanton 7's filled in - all of which with 1970's/80's slimline stanton columns. It's the same on the next road - two Stanton 7's (unsleeved, one with swan neck and one with quarter-circle bracket) still with timeswitches fitted, one at the end of the road and one halfway between that and the other end of the road, then slimline columns as infill.