I'm in the process of replacing the fuel gauge (s) on my Chief project. I bought a new one from Snyder Model A aircraft parts. Looks like it might work other than the fact I need to get the pin holes

in my main tank repaired. The auxilary tank is a different story as it has a 90 degree (or so) angle on the float arm so I decided to rebuild it. However neither the new glass nor the gaskets will fit in the space provided (too small). I'm thinking there must be a difference between the original and the replacement inner nut and I need to buy a new one. Has anyone ran into that before?? (Before I run out and buy a new one).
Thanks,
Mike