I've recently bought an IBM Model M SSK, and lo and behond, no key lock indicators! So after trying a few of the available programs out there, I decided to make my own.
I've posted the compiled AutoHotKey script at
https://www.autohotkey.com/boards/viewtopic.php?f=6&t=62611. It shows the keyboard indicators for the lock keys (NumLock, CapsLock and ScrollLock) in notification area of Taskbar in Windows. The few programs available with the same functionality didn't quite have the features or the icon legibility that I wanted. Notably it has different icon sizes for different Windows DPI scaling for maximum sharpness, a few color options, and the ability to configure it to only show when there are lock keys turned on.
Please feel free to post suggestions!