Riello mectron 3m oil burner leak?

I have a Riello 3m oil burner installed on a Burnham Jubilee furnance. The Riello burner has developed a small oil leak between the motor and pump and a slight amount of oil is seeping through the oil seal at the back of the pump and a drip every 15 minutes or so, I placed a small pan at the base of the burner to catch the oil. My question is:
Does Riello make a o ring kit to repair the problem or should I buy a new oil pump???? And since the Riello mectron 3m oil burner was replaced by the Riello F3 burner in 1990, will a F3 pump fit on my old burner?????? Any answers to this problem would be greatly appreciated. Thank you in advance for you time
John G.