If it's anything like the console on the 126, the panel has two "legs" just about even with the rear of the shiftgate opening. You have to set the panel inplace, a little forward of the final location and press down slightly while pushing the panel rearwards. That should engage the legs so they catch the cross bar of the console that is bolted to the rear of the shiftgate. Hope that makes sense.
Then once the rear is caught, the coin dish fits into the slot at the front of the panel and compresses the panel even further.
Hope this helps.
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72
'02 CLK320 Cabriolet - wifey's mid-life crisis
2012 VW Jetta Sportwagon TDI...at least its a diesel
Non illegitemae carborundum.