AGREE with all of the above, odds are your tranny is just fine and your linkage is the culprit. The offset to the drivers side is normal and expected. BEFORE you tear the whole **** shifter linkage out make a good, precise diagram of what is there now. Then get the mentioned above new shifter kit and install. Sounds like you had a mix of old and new, based on my personal terrible experiences with trying to figure this out on mine!
Question: How much vibe and movement of the shifter did you normally have prior to problem? Did it vibrate a little excessive at higher speeds? To the point where you felt better putting your right hand on it to calm down the vibration movement?