Not many buses with incandescent lighting still around, last ones we had over here that I remember were the original (not the awful replacement versions) London Routemasters. I got to drive one once, amazing experience

Here buses from the Ikarus brand were the last significant representatives of classic incandescent city bus lighting. In some cities they carried the torch to the beginning of this decade. Now they are all heritage status. Incandescent lit buses of other brands were retired much much earlier. Then again it isn't that weird considering that many Ikaruses with incandescent lighting were still made in 1997. Local preference and the manufacturer acted accordingly. Ikaruses made for the internal Hungarian market had fluorescent lighting already in the 80's. This was the case for the classic incandescents. If we expand the topic to also include halogens then there are still in use some second hand Man NG313 buses with 100% halogen lighting.

They started to fit the Routemasters with fluorescent tubes towards the end of their lives, the Green Line coach versions always had them. But the original buses had small 24V incandescents like this along each side above the windows. They'd go missing inside 5 minutes if they used them now

In different forms of transport in my country there were many changes of fixtures, fluorescent gear and power layout (single motor-alternator providing AC input versus DC input with individual transistor gear), so many that I can't count them all. However there are very few cases of light source type change in the era between first fluorescents and the moment just before LED revolution. Most fixture changes were incandescent to incandescent and fluorescent to fluorescent (often with tube wattage change). As for incandescent to fluorescent changes most of them were incidental, some small fractions of different types of incandescent trams were converted but most of those belonging to respective types remained as they were. I know of single trolleybuses which weren't suppossed to have incandescent lighting to begin with. Some now long gone pre-WW2 ex German EMUs before being introduced to service after war had undergone conversion but not all of them and the complete record didn't survive to modern times so exact numbers of EMUs with particular lighting type are unknown. There are two unique carriages from a larger group known as Ryflaki which were the only ones to be so deeply modernised. That's all for the moment, maybe I will remember more later. Conversions from full incandescent were rare but conversions of 90% fluorescent/10% incandescent and 97% fluorescent/3% incandescent to 100% fluorescent were actually quite popular. There is also a case of ex-Vienna trams in Kraków which originally had unique installation of incandescents and fluorescents electrically connected in series, those were converted to full electronic fluorescent. Worth mentioning are the cases of fluorescent to incandescent conversions. Long before aquiring the Vienna trams, Kraków aquired trams from Nuremberg which had fluorescent lighting but it was too troublesome so they went the easy way out and converted to incandescents. Another case is the modernisation of restaurant cars performed in previous decade. Originally those had fluorescent lighting but the design of the fixtures and the rest of the car was East German utilitarian and someone had problem with it. Therefore it was decided that the design after modernisation must be warm and cosy, so the combination of 90% halogen and 10% fluorescent was used. This was all before LEDs which I didn't include. After the popularisation of LEDs all Hell broke loose. There are many different conversions and mixes that include LEDs, some very weird:
https://www.lighting-gallery.net/gallery/displayimage.php?album=4353&pos=20&pid=154647