I'm kind of wondering if the Saginaw boxes and the Scout one have the same 32 spline sector. Found a place specializing in Scout parts and the flat one w/o any master splines is $89 while some of their drop offerings are ~$60-100. No idea on how good the steel is or if the temper is good or not....the flat one looks eerily similar to your PSC one though.
Check out the deal on Power Steering Pitman Arms for Custom Steering Applications at IH Parts America
www.ihpartsamerica.com
Check out the deal on Universal Saginaw Pitman Arm - Flat & Adjustable - Full Spline at IH Parts America
www.ihpartsamerica.com