Broke map sensor

Hi,just fitting a couple of O rings to original map sensor on my 07 plate 197 and the sensor broke leavening the stub flush in the manifold, upon trying to remove it it fell into the manifold! So I removed manifold to remove broke part hoping it didn’t fall into main engine,i could hear the bit rolling about the manifold but didn’t see it fall out.further movement of manifold I couldn’t hear broken part again.my issue is the broken tip of sensor going into main engine.also where can I buy a replacement map sensor now
Thanks mark