Since your scheme is separate from Bitcoin, it seems that it would be cumbersome for users: they would need to run a special client and keep it online for a long time. Also, how is the resulting mixing more secure than the server simply selling people Chaumian cash? It could be interesting to set up a mix-net rather than a single server, though.

If you simply want to experiment with blinding, for every 1.05 bitcoins you send me plus a blinded address, I would be more than happy to sign the blinded message, and for every fresh Bitcoin address you give me with my signature on it, I will send 1 coin to that address