I am trying to upgrade my early 80's Schwinn Continental's cranks. (and bottom bracket of course)

I got the Truvative American to Euro bottom bracket adapter, but I can't get it to work. As this photo hopefully illustrates, two out of three of the screw holes are partially blocked by an inner steel band. Unless I'm missing something? I've searched this forum and found a lot of posts suggesting that the adapter will work with Schwinns of that era, but perhaps mine is special?



Some helpful folks on a local bike forum suggested cutting through the inner band with a Dremel, and that will be my next step I guess, but I thought I'd post the question here also, given that the larger audience may include someone who's encountered this exact situation before and may have an alternative suggestion.

Following the advice in a couple of other threads here about not using the adapter screws to pull the two sides together, I cobbled together a DIY press with a huge bolt, a nut and some washers, but there is no point in pressing in the adapter if I can't screw the thing together.

Thanks in advance for any suggestions or advice.