I'm not sure exactly what winch
you have there. Is it labled "Custom..." or is it a custom built #22? I've not heard of such, myslef.
But the good news is that most of the sorta consumable bits in winches are to some degree interchangeable. Things like pawls, pawl springs and some bearings...
The Arco-Hutton winch company in Sydney
for older Barients and Barlows and some others. They would be a good source to investigate.
Meanwhile a photo
of your winch showing any ID markings might help us help you.