That looks like a Vintage a Speed classic. The base is a dead give away. I have one. https://store.vintagespeed.com...er-shifter-c33996772
The instructions I posted above should do the trick to help you adjust it. (If you want to give it a shot).
if not, and you are close to Greg, stop by his shop. Adjustments should take no more than 5-10 minutes.