A Site Dedicated to all enthusiasts of Classic Style Banjo
In my experience, there are small tears that don't affect the tone of the banjo - yet! But they do get worse, and it's best to get a new vellum. I see that yours is a zither-banjo - I've re-headed a Windsor zither-banjo myself, and it's not rocket science. Just follow the instructions for ordinary banjos by analogy. You can buy good vellums online from Clifford Essex or Stewart McDonald - I've tried both, and been quite satisfied with the results.
The first time I had a vellum split on me, I went running to a banjo repairman, who just said, "Do it yourself," and sold me a vellum, wrapped up in a photocopy of S.S. Stewart's instructions for putting a head on a banjo. Stewart obviously regarded this as a player's job - and he was right!