A Tribute to Shaheed Bhai Kulwant Singh Ji Nagoke:
A well written jeevani of Bhai Sahib ji can be found here at this link:
Sant Jarnail Singh Ji talks about the shaheedi of bhai sahib in their speeches. If you go to speech number 12 at the link posted above sant ji directly talks about the shaheedi of bhai sahib. You can feel that love and pain in their hearts as they talk.
Also I found this clip of Giani Jangbir Singh head kathavachak at sachkhand sri hazur sahib talk about bhai sahib ji and how close they were to sant ji.
There is also a video of sant ji talking about bhai sahib that can be found here: