Rich,
I'm sorry to say this, but it looks as if you will need to do 3 flight tests!
SE piston class rating should be a complete skill test, but as you are flying anyway, you may just get away with a revision flight and a test (see AIC 127/1999)
ME piston class, revision and test flight.
FI rating.. If you have not instructed for 3 years you will need to do the FI test for sure.
One of our chaps has just had his QFI downgraded to FI(R) as he has been out of it for two years... scary stuff !
If I were in your shoes, I would contact someone who could sort the lot out in one massaged go-- try Piers Smerdon on the QT.
he can be reached via Cabair Cranfield