You may be thinking of "Greek Enchiridion: A Concise Handbook of Grammar
for Translation and Exegesis" by William G. MacDonald and published by
Hendrickson in Peabody, Mass. It's about 8X5 and has a spiral binding so it
lays flat. I bought mine about 4 years ago and it cost $8-10. It was the
required grammar for a course in New Testament Greek at the Lutheran
Theological Seminary in Philadelphia.