Go for it Pauline babe!
Mrs P-B is a life-long adherent to the 'one door closes another one opens' school of thought and it took me 18 years to agree.
If your new boss (to be) has any sense he will see what a gem he has in you.
After all! He's called you back after maybe realising that the person he chose over you last time was the wrong choice - The others being interviewed are, of course, also in the running so...
Best foot forward, be positive, SMILE, but most of all, relax and tell him what a diamond you are!