Thank you both!
Confusion cleared up. Caused primarily by ops team using the term 'LPC' for 'Line Proficiency Check' as opposed to the more usual Licence Proficiency Check. All goes as you have both stated.
At least now I know I can revalidate my SPA-IR-ME by doing the L(icenc)PC for the MPA-IR and then doing sections 6 as SP. Very good.
Appreciate the help guys, sorry for being a bit slow on that one!