David, You can buy a new boom from Hartley Laminates;
http://www.hartleylaminates.co.uk/
I would imagine they could supply it with reefing kit if you wanted.
You probably have a fixed gooseneck on your mast – so that should be ok with a modern boom.
I’m not sure if booms come with a kicking strap band and mainsheet sliders – but if you need them make sure they come with the boom.
Hope that helps.