We are not familiar enough with the assembly of the sprayers to assist you properly and are not aware of any instructions available, however there are many technicians at B&G who can troubleshoot over the phone to assist you. You can reach B&G for support at 1-800-544-8811.
The B&G Valve Cable does not come with the seat stem attached. You would need to purchase the Seat Stem Part SS-158 and the Seat Stem Locknut Part SSL-157 separately.
We are unsure what you are asking. Please let us know what specific question you have about either the B&G wand or the B&G cable. The 18" Valve Cable would work as a replacement for your 18 inch wand if that is what you are trying to ask. Please let us know if you have any other questions.