Prowler - WIPC had a positive effect.

It wasn't the 31 bug but since one change fell within the overall tile data it was easy to predict where the change would happen.

$50e04 through $5489b = Level data (15,000 bytes)

$54057 - $50e04 = $3253 offset to WIPC changed byte

$3253 or 12883/300 = 42.943 level #

12883 MOD 300 = 283 remainder offset of tile within level

283/20 = 14.15 row

283 MOD 20 = 3 remainder column

Numbering from zero except for the level # which starts at 1

All this reduces to Level 43 row:14 column:3

This is the tile directly above the middle score digit. Go there and compare WIPC & WIPB. Obviously the new blue arrow is the correct one.

The other change that looked important to me was beyond the tile boundary so nothing to report on it.