Common misconception actually, the 3.5 version of spellstitched is in Complete Arcane. LM merely references it in a table, the MMII version specifically, although that's purely because CA came out a month after LM.
The sample Spellstitched in CA has a LA: -, but so does the base Ghast, so that's nothing to go by. The template itself has no LA entry, just a CR one.