Key is FINAL VICTORY with clockwise spiral insertion.
Solved with pencil and paper by dragging crib texts through
cipher text and attempting to recover a viable matrix to
determine when correct position found.
Comments from Jim Gillogly
Martin doesn't give much detail, but he alludes to the key
idea in starting a Playfair with a crib: the operation called
"crib dragging." This is important in the solution of many
kinds of ciphers when a crib is available: Try the crib at
each position in turn and see whether you can find
contradictions or confirmations, or make further deductions
based on that position. Crib dragging can be done effectively
by eyeball or with a computer program.