to fix the rubber joint in the first pic you can use something like this

www.surfsailaustralia.com.au/shop

but that bombora base plate will be harder to fix your best bet would be to find something like this

isthmussailboards.com/chinook-brass-slider-for-mistral-track.html

you can slot it into the mast track and attach any modern base to it but you will lose the ability to slide the track back and forth.

I'm assuming it from a long board like a South Pacific or a Capricorn or Big toy ?

good luck.