If you managed to score a ML pre of ANY vintage (you didn't say;-) then it seems to me (optimist that I am) you should be able to afford a respectable amp to go with it. Respectable, meaning not necessarily even a used Levinson, but still, something more in keeping with the Levinson's quality. Further, depending on your particular speakers, you may want to pair the Levinson pre with a good tube amp. That's what I did.
.
.