Power steering pump drive

[fredtporter]

My power steering died the other day and there was a rattle from the link between alternator and pump. I have taken it apart and found the arrangement in the pics attached. Is anyone familiar with it? The previous owner fitted it and it seems quite new. I have filed down some ridges on the dog and put it back together - seems to fit ok but haven’t tested again yet. would like to know where I could get parts for this. Looks like the drive link on the pump itself is a bit worn - don’t suppose you can repair such a thing. Also would like to get a new dog as a backup but it doesn’t look like the one on SNG...