The COB flexible LED strips are also available at
https://theelectronicgoldmine.com/collections/string-ledsThey have dozens of LEDs inside a soft tubular shape. The diameter is much larger than N scale fluorescent tube would be, but if that is not important, these will work well. Of course at their as-designed brightness they are way too bright for scale illumination, but they can be powered at reduced current (brightness). When running at lower brightness the individual LEDs become apparent. The other thing is that these are only available from this vendor as warm white. Fluorescent lighting usually has a cool white look.
Since the power is applied to the ends, these cannot be trimmed to length, but multiple lengths are available.
I suspect if one would do some Internet searches, similar products will be found elsewhere (and also in cool white). Maybe try amazon or eBay.
