Light aircraft pilot reported an NMAC with a light twin shortly after takeoff from SPB.

Narrative

I waited for takeoff at the hold short line for runway 33 on the east taxiway for a break in traffic in the pattern; listening for traffic calling position reports. I could see and heard a radio call from a Aircraft X on base; turning to final. Following a departing Aircraft Y who took the runway from the west taxiway; I announced my departure to make right closed traffic and took the runway. As I was lifting off the runway I saw the shadow of an airplane on the ground to my left. Shortly after; I saw Aircraft Y pass over me to my left; and heard someone announce a go-around. I had not seen the aircraft or heard the pilot announce his position in the pattern.I followed the aircraft around the pattern. I saw that on base; the pilot extended his base leg well to the west of the extended runway centerline; and made a very flat approach to the runway. The aircraft landed and exited the runway to the west taxiway to taxi back to runway 33. I landed after the aircraft had cleared the runway and exited to the east taxiway and continued to the parking ramp.I believe that Aircraft Y might have been making an approach similar to that which I observed where the aircraft would not have been obvious to me looking out at the final approach to runway 33; as it would have been well to the west and low; possibly obscured by trees from my position on the taxiway. Aircraft X on base to final I could see; as that aircraft was in the proper position and altitude in the pattern.