Parties unknown have placed the passenger front seat back in its full reclining position and the manual control will not allow the seat to return to its upright position. I fear that the only recourse is to pull the seat from van. Any tips and or suggestions would be greatly appreciated.

Welcome to the forum Nick. Is the handle still intact?
I am wondering if you tried to just push it back even slightly and tried the handle, to see if it will release...
Hopefully others will chime in with some ideas on the Van. You may have to pull the seat to see what is really going on. \
Stopping by a body shop, they may also may know what is up or more like down...LOL.

If it isn't a power seat I would suggest you have someone sit in the seat and bounce on the back rest while you try and release it. If it'* a power seat I bet the motor burnt out in that case the seat needs to come out.

Remove the plastic seat side shields and see how the handle connects to the release mechanism. Some of them are connected by cable, and the cable can get disconnected from the mechanism.

What is your hesitation at taking the seat out? Undo four bolts and out she comes. My advice is pull the seat ... no matter what the problem is pulling the seat will make it easier to diagnose and repair. If you have never pulled a seat before, it is very easy to do and does not take long at all.