Inspection revealed a couple discoveries
• 2 Screws were missing - minor issue, both were replaced
• A wire to one of the solenoid leads was routed over another hot wire. The insulation was melted and deteriorating. I believe this was inadvertently drawing power away from the action necessary to project force to the ball. I rerouted the wire and covered the defect with electric tape.

Note: During testing I accidentally caused a short and blew the fuse (5A MDL). The fuse was replaced.

Conclusion: The flipper power is working as intended. Problem resolved.