I have a detachable towbar fitted to the scooby but no ball (please no jokes )

The bracket has the P/no L1010SE100 38.4011 on it which I can find no problem as its a original subaru part, but all I need is the ball part, has anyone got any ideas where I can find the part number for the ball or if I can buy just the ball?

I have seen a few on ebay but they seem to be witter which looks different.

Thanks in advance

John