Merc TR Outdrive Stuck in Down Position
 

I have a well cared for 1986 Merc TR outdrive stuck in the down position. It won't budge. It is driven by a borg warner velvet drive transmission. I removed the hydraulic rams and still won't budge under force. Thinking the hinge pins might be frozen I removed them and the outdrive still won't move under Notable Force. Is there a lockout of some kind? What else could it be? Any suggestions or insights are welcome. Thank You!