This one is easier. Just record yourself a lot, and if you can use the same mic even better. Eventually the mic just becomes another piece of kit.
Remember, you play well. That’s why they asked you to do this. So do what it is you do. No more, no less. No pressure.
And I KNOW you play well (and I bet you play even better than when I last heard you!)! Carey’s right. It’s time and mileage at this point, and recording yourself is a GOOD thing (remember Kev’s drone idea?).
And hey. Look at it this way. At least it wasn’t a folk festival in Ennis. 
XO!