I am currently designing a Raspberry Pi audio HAT using the Nutube 6P1 (flat vaccum tube). I'd like to talk about the process involved in the conception and execution of such projects.
How to put together a non-trivial hardware design from reference designs.
Hardware development process
Hardware ecosystem in India
This has a lot of potential to be a very informative talk. Be sure to have a lot of pictures and/or video.
Be sure to explain your journey to why you wanted to make this thing as well as the making of it. There may be many who have never considered making hardware, but would be inspired by your journey.