The 9 shilling denomination was also know as a 'Silver' note. The Ross Bank had two registered partners, George Roe and his brother Peter. This one is signed by Peter Roe.
I attach a later example of a 4 Guinea note from this bank. This denomination is readily available to collectors as a hoard of partly issued and non-issued notes was discovered some time ago. The attached note is a fully issued example from 1814.