Upon further inspection in comparison I can see that at some point it's life somebody has changed the speaker binding posts. Someone also removed the game pots and in their place moved the RCA input jacks. So now I have two holes where the jacks used to be and input jacks where the gain knobs used to be. It's like being an audio detective!

You are welcome... yes, that should do it. Correctly connect the plus and minus+- wires and may need to gently pry open with a small screwdriver or knife blade after removing screws. When you open, check your wires for connection. More than 1 person has replaced when not needed. Sometimes just loose connection so, check connection on the back, etc. from the power source. Another check is to try supposed bad speaker to a known good source with a short speaker wire... @Quentin-Mania

You're absolutely correct that that is the same model. Thank you so much for that!   After going through that thread and seeing an image with the exact writing on the bottom of the authors amplifier I am 100% sure that I have that same exact amplifier in my setup right now. If you compare the writing on the bottom of his to the writing of the one I posted in my first post it's identical. Looking at the author's location they are in Florida. I am in Baltimore. This amp is traveled. I understand that Will Vincent is on the west coast somewhere maybe Idaho? Already you guys and gals have helped me figure out some of this amplifiers history. Whenever I have pieces like this I absolutely love it and love finding where they've been and to know how they travel to end up in my room!

Thanks for welcoming me, I really appreciate that. 😊   I just have to remove the four screws, then unplug the cable inside the speaker and remember where I have to connect it again. Then reattach the four screws. No Power to the woofer is important. Is it better to let the speaker stand or change better horizontally? And is it easy to recognize Plus and Minus, don‘t wanna make a mistake.    thanks in advance for all the very good advices.   best regards  Quentin

Welcome @Quentin-Mania... nothing unless you want to. Any questions or concerns? No power to the woofer when replacing.    

As a debilitated old fart this Bill Gaither song says it all!!!   Maynard    

Is it easy to replace the woofer, are there any specific things I have to mention? 

For some early evening entertainment. A 1979 US pressing of -   Artist - Pink Floyd  Title - The Wall    

Yesterday we had a little shindig in downtown Spruce Pine.   Some friends of mine were helping to run things backstage and as soon as I showed up they threw a backstage pass at me and my told me to grab a camera and start shooting.