Unfortunately, the planer is broken again. The blade pulley has cracked off part of the groove that holds onto the alignment key, and prevents the pulley from slipping or throwing the belt. The final time I fired it up, the pulley immediately slipped on the shaft, and shot a spark as the alignment key became dislodged and sheared apart. The spare pulley in the disassembled planer has cracks in the same place, so just replacing it might mean the same issue materializing very soon, but both alignment keys are now gone. (See attached photo for cracked spare pulley, existing pulley has the cracked part missing entirely)
A replacement pulley and key can be ordered on eBay, arriving in 10 day- 2 weeks. I might also look to order a new blade shaft, in case the groove for the alignment key is worn and will start the cycle of damage to the pulley again. Either way, the tool needs to be partially disassembled to swap the pulley, so hopefully I can get it working again before the Grand opening.