In searching the vast annals of the internet, I have come across an old (2008) thread on rpg.net that seems to imply that there once existed an exp-based scheme for advancement that removed levels from Spycraft--I would love to get my hands on this document but I cannot find it.
Furthermore, there was also discussion in that thread about someone making a mutants and mastermind conversion for spycraft while I would also be interested in. I think it was by Berin Kinsman.
Thank you all for taking the time to read my request.
My best wishes.