ROTJ thermal detonator - help needed on specs please?

I was thinking about this for my next project.

I would like to know some specs like the size, measurements etc from someone who has one (MR etc). I'm looking to scratchbuild, not cast, and it will likely be made of metal (I like an authentic feel, even though the prop was probably resin originally). I've had some difficulties tracking down info on the www.

Can anyone help?

You might want start HERE

If you want a metal scratchbuild you may want to look into the ice cream scoop thermal detonator.