Ronnie Raygun.

Named in honor of president Reagan's "Star Wars" initiative.

I am not providing specific instructions simply because if you obtain an old hand held timing light it would likely be totally different from this particular model.  Any pistol grip type light will work.  Not rocket science.

I just opened the case, stripped out the original components including the cables that formerly exited the handle and inserted a basic  2xAA battery holder.  Keeping the original trigger switch in series with a standard laser module, I put it all back in.

The original flash tube was held with a black rubber ring which proved to be a suitable mount for the laser so I used that as well.

Screwed it all back together and VOILA!  I have a ray gun!  Total build time, probably about fifteen minutes.  Enjoy.